Related
I've read all the questions and answer and all the tutorial about this subject, but for some reason it's not working for me. always showing me that the two dates are the same date!
Please some one help me to figure it out, I just want to check if one is bigger than the other (including date and time - without seconds) or if they are equal.
This is my code:
- (BOOL)isEndDateIsBiggerThanCurrectDate:(NSDate *)checkEndDate
{
NSString *endd = [NSDateFormatter localizedStringFromDate:checkEndDate
dateStyle:NSDateFormatterShortStyle
timeStyle:NSDateFormatterShortStyle];
NSString *curreeeent = [NSDateFormatter localizedStringFromDate:[NSDate date]
dateStyle:NSDateFormatterShortStyle
timeStyle:NSDateFormatterShortStyle];
NSDateFormatter * df = [[NSDateFormatter alloc]init];;
NSDate * newCurrent = [df dateFromString:endd];
NSDate * newEnd = [df dateFromString:curreeeent];
switch ([newCurrent compare:newEnd])
{
case NSOrderedAscending:
return YES;
break;
case NSOrderedSame:
return NO;
break;
case NSOrderedDescending:
return NO;
break;
}
}
Thank you very much!
For this, you have to use NSCalender.
NSCalendar *calendar = [NSCalendar currentCalendar];
NSInteger desiredComponents = (NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit);
NSDateComponents *firstComponents = [calendar components:desiredComponents fromDate:[NSDate date]];
NSDateComponents *secondComponents = [calendar components:desiredComponents fromDate: checkEndDate];
NSDate *first = [calendar dateFromComponents:firstComponents];
NSDate *second = [calendar dateFromComponents:secondComponents];
NSComparisonResult result = [first compare:second];
if (result == NSOrderedAscending) {
//checkEndDate is before now
} else if (result == NSOrderedDescending) {
//checkEndDate is after now
} else {
//both are same
}
You should really be using time intervals rather than converting between dates and strings.
Something like the following should suit your needs:
//current time
NSDate *now = [NSDate date];
//time in the future
NSDate *distantFuture = [NSDate distantFuture];
//gather time interval
if([now timeIntervalSinceDate:distantFuture] > 0)
{
//huzzah!
}
I've got the answer, just checking the exact time between two dates and compare it.
- (BOOL)isEndDateIsSmallerThanCurrent:(NSDate *)checkEndDate
{
NSDate* enddate = checkEndDate;
NSDate* currentdate = [NSDate date];
NSTimeInterval distanceBetweenDates = [enddate timeIntervalSinceDate:currentdate];
double secondsInMinute = 60;
NSInteger secondsBetweenDates = distanceBetweenDates / secondsInMinute;
if (secondsBetweenDates == 0)
return YES;
else if (secondsBetweenDates < 0)
return YES;
else
return NO;
}
Why don't you change the dates into time interval since 1970 and sort by that. Extremely simple number compare, much quicker than string compare, and they will always sort correct, not like 1,10,11,2,21,22,3,....
NSDate *now = [NSDate date];
NSTimeInterval ti = [now timeIntervalSince1970];
Thats it. No new object creations, much quicker and much less taxing on the cpu.
See here how you get rid of seconds, but it is easy because you have numbers, for seconds. See here How to set seconds to zero for NSDate
I have an issue related to calculating business days in Objective-C.
I need to add X business days to a given NSDate.
For example, if I have a date: Friday 22-Oct-2010, and I add 2 business days, I should get: Tuesday 26-Oct-2010.
Thanks in advance.
There are two parts to this:
Weekends
Holidays
I'm going to pull from two other posts to help me out.
For weekends, I'm going to need to know a given date's day of the week. For that, this post comes in handy:
How to check what day of the week it is (i.e. Tues, Fri?) and compare two NSDates?
For holidays, #vikingosegundo has a pretty great suggestion on this post:
List of all American holidays as NSDates
First, let's deal with the weekends;
I've wrapped up the suggestion in the post I cited above into this nice little helper function which tells us if a date is a weekday:
BOOL isWeekday(NSDate * date)
{
int day = [[[NSCalendar currentCalendar] components:NSWeekdayCalendarUnit fromDate:date] weekday];
const int kSunday = 1;
const int kSaturday = 7;
BOOL isWeekdayResult = day != kSunday && day != kSaturday;
return isWeekdayResult;
}
We'll need a way to increment a date by a given number of days:
NSDate * addDaysToDate(NSDate * date, int days)
{
NSDateComponents * components = [[NSDateComponents alloc] init];
[components setDay:days];
NSDate * result = [[NSCalendar currentCalendar] dateByAddingComponents:components toDate:date options:0];
[components release];
return result;
}
We need a way to skip over weekends:
NSDate * ensureDateIsWeekday(NSDate * date)
{
while (!isWeekday(date))
{
// Add one day to the date:
date = addDaysToDate(date, 1);
}
return date;
}
And we need a way to add an arbitrary number of days to a date:
NSDate * addBusinessDaysToDate(NSDate * start, int daysToAdvance)
{
NSDate * end = start;
for (int i = 0; i < daysToAdvance; i++)
{
// If the current date is a weekend, advance:
end = ensureDateIsWeekday(end);
// And move the date forward by one day:
end = addDaysToDate(end, 1);
}
// Finally, make sure we didn't end on a weekend:
end = ensureDateIsWeekday(end);
return end;
}
Note; There is an obvious optimization I skipped - you could easily add more than one day at a time to the current date - but the point of my post is to show you how to do this yourself - and not necessarily to come up with the best possible solution.
Now lets tie that up and see what we have so far:
int main() {
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
NSDate * start = [NSDate date];
int daysToAdvance = 10;
NSDate * end = addBusinessDaysToDate(start, daysToAdvance);
NSLog(#"Result: %#", [end descriptionWithCalendarFormat:#"%Y-%m-%d"
timeZone:nil
locale:nil]);
[pool drain];
return 0;
}
So, we've got weekends covered, now we need to pull in the holidays.
Pulling in some RSS feed, or data from another source is definitely beyond the scope of my post... so, let's just assume you have some dates you know are holidays, or, according to your work calendar, are days off.
Now, I'm going to do this with an NSArray... but, again, this leaves plenty of room for improvement - at minimum it should be sorted. Better yet, some sort of hash set for fast lookups of dates. But, this example should suffice to explain the concept. (Here we construct an array which indicates there are holidays two and three days from now)
NSMutableArray * holidays = [[NSMutableArray alloc] init];
[holidays addObject:addDaysToDate(start, 2)];
[holidays addObject:addDaysToDate(start, 3)];
And, the implementation for this will be very similar to the weekends. We'll make sure the day isn't a holiday. If it is, we'll advance to the next day. So, a collection of methods to help with that:
BOOL isHoliday(NSDate * date, NSArray * holidays)
{
BOOL isHolidayResult = NO;
const unsigned kUnits = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit;
NSDateComponents * components = [[NSCalendar currentCalendar] components:kUnits fromDate:date];
for (int i = 0; i < [holidays count]; i++)
{
NSDate * holiday = [holidays objectAtIndex:i];
NSDateComponents * holidayDateComponents = [[NSCalendar currentCalendar] components:kUnits fromDate:holiday];
if ([components year] == [holidayDateComponents year]
&& [components month] == [holidayDateComponents month]
&& [components day] == [holidayDateComponents day])
{
isHolidayResult = YES;
break;
}
}
return isHolidayResult;
}
and:
NSDate * ensureDateIsntHoliday(NSDate * date, NSArray * holidays)
{
while (isHoliday(date, holidays))
{
// Add one day to the date:
date = addDaysToDate(date, 1);
}
return date;
}
And, finally, make some modifications to our addition function to take into account the holidays:
NSDate * addBusinessDaysToDate(NSDate * start, int daysToAdvance, NSArray * holidays)
{
NSDate * end = start;
for (int i = 0; i < daysToAdvance; i++)
{
// If the current date is a weekend, advance:
end = ensureDateIsWeekday(end);
// If the current date is a holiday, advance:
end = ensureDateIsntHoliday(end, holidays);
// And move the date forward by one day:
end = addDaysToDate(end, 1);
}
// Finally, make sure we didn't end on a weekend or a holiday:
end = ensureDateIsWeekday(end);
end = ensureDateIsntHoliday(end, holidays);
return end;
}
Go ahead and try it:
int main() {
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
NSDate * start = [NSDate date];
int daysToAdvance = 10;
NSMutableArray * holidays = [[NSMutableArray alloc] init];
[holidays addObject:addDaysToDate(start, 2)];
[holidays addObject:addDaysToDate(start, 3)];
NSDate * end = addBusinessDaysToDate(start, daysToAdvance, holidays);
[holidays release];
NSLog(#"Result: %#", [end descriptionWithCalendarFormat:#"%Y-%m-%d"
timeZone:nil
locale:nil]);
[pool drain];
return 0;
}
If you want the whole project, here ya go: http://snipt.org/xolnl
There's nothing built into NSDate or NSCalendar that counts business days for you. Business days depend to some degree on the business in question. In the US, "business day" generally means weekdays that aren't holidays, but each company determines which holidays to observe and when. For example, some businesses move observance of minor holidays to the last week of the year so that employees can be off between Christmas and New Year's Day without taking vacation.
So, you'll need to decide exactly what you mean by business day. It should then be simple enough write a little method to calculate a future date by adding some number of business days. Then use a category to add a method like -dateByAddingBusinessDays: to NSDate.
this answer is late to the party but…. I thought i might improve on above answers to determine business days by working with NSDateComponents directly of your date in a nice loop.
#define CURRENTC [NSCalendar currentCalendar]
#define CURRENTD [NSDate date]
NSInteger theWeekday;
NSDateComponents* temporalComponents = [[NSDateComponents alloc] init];
[temporalComponents setCalendar:CURRENTC];
[temporalComponents setDay: 13];
[temporalComponents setMonth: 2];
[temporalComponents setYear: theYear];
// CURRENTC =the current calendar which determines things like how
// many days in week for local, also the critical “what is a weekend”
// you can also convert a date directly to components. but the critical thing is
// to get the CURRENTC in, either way.
case 3:{ // the case of finding business days
NSDateComponents* startComp = [temporalComponents copy]; // start date components
for (int i = 1; i <= offset; i++) //offset is the number of busi days you want.
{
do {
[temporalComponents setDay: [temporalComponents day] + 1];
NSDate* tempDate = [CURRENTC dateFromComponents:temporalComponents];
theWeekday = [[CURRENTC components:NSWeekdayCalendarUnit fromDate:tempDate] weekday];
} while ((theWeekday == 1) || (theWeekday == 7));
}
[self findHolidaysStart:startComp end:temporalComponents]; // much more involved routine.
[startComp release];
break;
}
// use startComp and temporalcomponents before releasing
// temporalComponents now contain an offset of the real number of days
// needed to offset for busi days. startComp is just your starting date….(in components)
// theWeekday is an integer between 1 for sunday, and 7 for saturday, (also determined
// by CURRENTC
turning this back into NSDate, and you are done. Holidays are much more involved.. but can actually be calculated if just using federal holidays and a few others. because they are always something like “3rd monday of January”
here is what the findHolidaysStart:startComp end: starts out like, you can imagine the rest.
// imported
[holidayArray addObject:[CURRENTC dateFromComponents:startComp]];
[holidayArray addObject:[CURRENTC dateFromComponents:endComp]];
// hardcoded
dateComponents = [[NSDateComponents alloc] init];
[dateComponents setCalendar:CURRENTC];
[dateComponents setDay: 1];
[dateComponents setMonth: 1];
[dateComponents setYear: theYear];
theWeekday = [[CURRENTC components:NSWeekdayCalendarUnit fromDate:[CURRENTC dateFromComponents:dateComponents]] weekday];
if (theWeekday == 1) [dateComponents setDay:2];
if (theWeekday == 7) {[dateComponents setDay:31]; [dateComponents setYear: theYear-1];}
[holidayArray addObject:[CURRENTC dateFromComponents:dateComponents]];
[dateComponents release];
I took #steve's answer and added a method to calculate the days of all the federal holidays in USA and put it all in a Category. I've tested it and it works nicely. Check it out.
#import "NSDate+BussinessDay.h"
#implementation NSDate (BussinessDay)
-(NSDate *)addBusinessDays:(int)daysToAdvance{
NSDate * end = self;
NSArray *holidays = [self getUSHolidyas];
for (int i = 0; i < daysToAdvance; i++)
{
// Move the date forward by one day:
end = [self addDays:1 toDate:end];
// If the current date is a weekday, advance:
end = [self ensureDateIsWeekday:end];
// If the current date is a holiday, advance:
end = [self ensureDateIsntHoliday:end forHolidays:holidays];
}
return end;
}
#pragma mark - Bussiness Days Calculations
-(BOOL)isWeekday:(NSDate *) date{
int day = (int)[[[NSCalendar currentCalendar] components:NSWeekdayCalendarUnit fromDate:date] weekday];
const int kSunday = 1;
const int kSaturday = 7;
BOOL isWeekdayResult = day != kSunday && day != kSaturday;
return isWeekdayResult;
}
-(NSDate *)addDays:(int)days toDate:(NSDate *)date{
NSDateComponents * components = [[NSDateComponents alloc] init];
[components setDay:days];
NSDate * result = [[NSCalendar currentCalendar] dateByAddingComponents:components toDate:date options:0];
return result;
}
-(NSDate *)ensureDateIsWeekday:(NSDate *)date{
while (![self isWeekday:date])
{
// Add one day to the date:
date = [self addDays:1 toDate:date];
}
return date;
}
-(BOOL)isHoliday:(NSDate *)date forHolidays:(NSArray *)holidays{
BOOL isHolidayResult = NO;
const unsigned kUnits = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit;
NSDateComponents * components = [[NSCalendar currentCalendar] components:kUnits fromDate:date];
for (int i = 0; i < [holidays count]; i++)
{
NSDate * holiday = [holidays objectAtIndex:i];
NSDateComponents * holidayDateComponents = [[NSCalendar currentCalendar] components:kUnits fromDate:holiday];
if ([components year] == [holidayDateComponents year]
&& [components month] == [holidayDateComponents month]
&& [components day] == [holidayDateComponents day])
{
isHolidayResult = YES;
break;
}
}
return isHolidayResult;
}
-(NSDate *)ensureDateIsntHoliday:(NSDate *)date forHolidays:(NSArray *)holidays{
while ([self isHoliday:date forHolidays:holidays])
{
// Add one day to the date:
date = [self addDays:1 toDate:date];
}
return date;
}
-(NSArray *)getUSHolidyas{
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
formatter.dateFormat = #"yyyy";
NSString *year = [formatter stringFromDate:[NSDate date]];
NSString *nextYear = [formatter stringFromDate:[NSDate dateWithTimeIntervalSinceNow:(60*60*24*365)]];
formatter.dateFormat = #"M/d/yyyy";
//Constant Holidays
NSDate *newYearsDay = [formatter dateFromString:[NSString stringWithFormat:#"1/1/%#",nextYear]]; //Use next year for the case where we are adding days near end of december.
NSDate *indDay = [formatter dateFromString:[NSString stringWithFormat:#"7/4/%#",year]];
NSDate *vetDay = [formatter dateFromString:[NSString stringWithFormat:#"11/11/%#",year]];
NSDate *xmasDay = [formatter dateFromString:[NSString stringWithFormat:#"12/25/%#",year]];
//Variable Holidays
NSInteger currentYearInt = [[[NSCalendar currentCalendar]
components:NSYearCalendarUnit fromDate:[NSDate date]] year];
NSDate *mlkDay = [self getTheNth:3 occurrenceOfDay:2 inMonth:1 forYear:currentYearInt];
NSDate *presDay = [self getTheNth:3 occurrenceOfDay:2 inMonth:2 forYear:currentYearInt];
NSDate *memDay = [self getTheNth:5 occurrenceOfDay:2 inMonth:5 forYear:currentYearInt]; // Let's see if there are 5 Mondays in May
NSInteger month = [[[NSCalendar currentCalendar] components:NSYearCalendarUnit fromDate:memDay] month];
if (month > 5) { //Check that we are still in May
memDay = [self getTheNth:4 occurrenceOfDay:2 inMonth:5 forYear:currentYearInt];
}
NSDate *labDay = [self getTheNth:1 occurrenceOfDay:2 inMonth:9 forYear:currentYearInt];
NSDate *colDay = [self getTheNth:2 occurrenceOfDay:2 inMonth:10 forYear:currentYearInt];
NSDate *thanksDay = [self getTheNth:4 occurrenceOfDay:5 inMonth:11 forYear:currentYearInt];
return #[newYearsDay,mlkDay,presDay,memDay,indDay,labDay,colDay,vetDay,thanksDay,xmasDay];
}
-(NSDate *)getTheNth:(NSInteger)n occurrenceOfDay:(NSInteger)day inMonth:(NSInteger)month forYear:(NSInteger)year{
NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
dateComponents.year = year;
dateComponents.month = month;
dateComponents.weekday = day; // sunday is 1, monday is 2, ...
dateComponents.weekdayOrdinal = n; // this means, the first of whatever weekday you specified
return [[NSCalendar currentCalendar] dateFromComponents:dateComponents];
}
#end
I'm attempting to get around a date validation that refuses to take anything earlier than tomorrow.
So far I have this:
NSDate *dateY = [NSDate dateWithTimeIntervalSinceNow:-86400];
// Negative one day, in seconds (-60*60*24)
NSLog(#"%#", [NSDate date]);
// "yyyy-MM-dd HH:mm:ss Z", accurate assuming Z = +0000
NSLog(#"%#", dateY);
// "yyyy-MM-dd HH:mm:ss Z", same accuracy (minus one day)
That's great, but dateY is not an NSNumber. I need an NSNumber for the comparison, but I can't find anything that works. (I don't even know how an NSNumber can be 2011-04-14 13:22:29 +0000, anyway...)
I can use NSDateFormatter to convert an NSDate into an NSString, so if it would be possible to take that string and convert it to the required NSNumber (as opposed to directly converting the NSDate to an NSNumber, which I can't seem to find help with either), that would be fine.
- (BOOL)validateDueDate:(id *)ioValue error:(NSError **)outError {
NSDate *dateY = [NSDate dateWithTimeIntervalSinceNow:-86400];
NSNumber *tis1970 = [NSNumber numberWithDouble:[dateY timeIntervalSince1970]];
NSLog(#"NSNumber From Date : %#", tis1970);
NSLog(#"Date From NSNumber : %#", [NSDate dateWithTimeIntervalSince1970:[tis1970 doubleValue]]);
// Due dates in the past are not valid
// Enforced that a due date has to be >= today's date
if ([*ioValue compare:[NSDate date]] == NSOrderedAscending) {
if (outError != NULL) {
NSString *errorStr = [[[NSString alloc] initWithString:#"Due date must be today or later."] autorelease];
NSDictionary *userInfoDictionary = [NSDictionary dictionaryWithObject:errorStr forKey:#"ErrorString"];
NSError *error = [[[NSError alloc]
initWithDomain:TASKS_ERROR_DOMAIN
code:DUEDATE_VALIDATION_ERROR_CODE
userInfo:userInfoDictionary] autorelease];
*outError = error;
}
return NO;
} else {
return YES;
}
}
Right now, the user is not allowed to choose a date before tomorrow. errorStr lies. Before today makes more sense than before tomorrow as a rule for refusing to save the date, so I've been fighting with this thing to let me use yesterday in place of today, rather than looking any deeper.
Edit: Using NSOrderedSame allows any date to be selected without an error. That won't do.
You can convert an NSDate to an NSNumber like this:
NSDate *aDate = [NSDate date];
NSNumber *secondsSinceRefDate = [NSNumber numberWithDouble:[aDate timeIntervalSinceReferenceDate]];
and convert back like:
aDate = [NSDate dateWithTimeIntervalSinceReferenceDate:[NSNumber doubleValue]];
All that is needed to get a NSNumber is
NSDate *dateY = [NSDate dateWithTimeIntervalSinceNow:-86400];
NSNumber *tis1970 = [NSNumber numberWithDouble:[dateY timeIntervalSince1970]];
NSLog(#"NSNumber From Date : %#", tis1970);
NSLog(#"Date From NSNumber : %#", [NSDate dateWithTimeIntervalSince1970:[tis1970 doubleValue]]);
You should never use 86400 to calculate date differences, because not all days have 86,400 seconds in them. Use NSDateComponents instead:
- (BOOL)validateDueDate:(NSDate *)dueDate error:(NSError *)error {
NSDate *today = [NSDate date];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit) fromDate:today];
//adjust the components to tomorrow at the first instant of the day
[components setDay:[components day] + 1];
[components setHour:0];
[components setMinute:0];
[components setSecond:0];
NSDate *tomorrow = [calendar dateFromComponents:components];
NSDate *earlierDate = [dueDate earlierDate:tomorrow];
if ([earlierDate isEqualToDate:dueDate]) {
//the dueDate is before tomorrow
if (error != nil) {
NSString *errorStr = [[[NSString alloc] initWithString:#"Due date must be today or later."] autorelease];
NSDictionary *userInfoDictionary = [NSDictionary dictionaryWithObject:errorStr forKey:NSLocalizedDescriptionKey];
*error = [[[NSError alloc] initWithDomain:TASKS_ERROR_DOMAIN code:DUEDATE_VALIDATION_ERROR_CODE userInfo:userInfoDictionary] autorelease];
}
return NO;
}
return YES;
}
WARNING: code typed in a browser. Caveat Implementor
I’m trying to make a counter which shows the number of days until we leave on a trip to Europe. It’s only about 70 days (as of today) so I don’t believe that I should have to worry about astronomically large numbers or anything, but I really am stumped - I’ve attached the code that some friends have given me, which don’t work either. Trust me when I say I’ve tried everything I can think of - and before anyone bites my head off, which I have seen done on these forums, yes I did look very extensively at the Apple Documentation, however I’m not 100% sure where to start - I’ve tried NSTimer, NSDate and all their subclasses and methods, but there’s nothing that jumps out immediately.
In terms of what I think I should actually be doing, I think I need to somehow assign an integer value for the “day” today/ now/ the current day, which will change dynamically using the [NSDate date] and then the same for the date that we leave. The countdown is just updating when the method gets called again (I can do this using NSTimer if need be) and the value that is displayed on the countdown is the differnce between these two values.
I don’t especially want to have a flashing kind of thing that updates every second until we leave - personally I think that’s tacky, but if anyone knows how then I’d appreciate it for future reference.
I’ve also done an extensive search of google, and I may simply be using the wrong search terms, but I can’t find anything there either.
Any help is greatly appreciated.
Thank you very much.
Michaeljvdw
- (void)countDownMethod {
NSDateComponents *comps = [[NSDateComponents alloc] init];
[comps setDay:startDay];
[comps setMonth:startMonth];
[comps setYear:startYear];
[comps setHour:startHour];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDate *date = [gregorian dateFromComponents:comps];
NSLog(#"%#",date);
[gregorian release];
[comps release];
NSTimeInterval diff = [date timeIntervalSinceNow];
int diffInt = diff;
NSString *days = [NSString stringWithFormat:#"%d",diffInt/86400];
day0.text = #"0";
day1.text = #"0";
day2.text = #"0";
NSLog(#"Days Length: %d",days.length);
if(days.length >= 1){
day2.text = [days substringFromIndex:days.length - 1];
if(days.length >= 2){
day1.text = [days substringWithRange:NSMakeRange(days.length - 2, 1)];
if(days.length >= 3){
day0.text = [days substringWithRange:NSMakeRange(days.length - 3, 1)];
}
}
}
NSString *hours = [NSString stringWithFormat:#"%d",(diffInt%86400)/3600];
hour0.text = #"0";
hour1.text = #"0";
NSLog(#"Hours Length: %d",hours.length);
if(hours.length >= 1){
hour1.text = [hours substringFromIndex:hours.length - 1];
if(hours.length >= 2){
hour0.text = [hours substringWithRange:NSMakeRange(hours.length - 2, 1)];
}
}
NSString *minutes = [NSString stringWithFormat:#"%d",((diffInt%86400)%3600)/60];
minute0.text = #"0";
minute1.text = #"0";
NSLog(#"Minutes Length: %d",minutes.length);
if(minutes.length >= 1){
minute1.text = [minutes substringFromIndex:minutes.length - 1];
if(minutes.length >= 2){
minute0.text = [minutes substringWithRange:NSMakeRange(minutes.length - 2, 1)];
}
}
}
If you know the time in seconds between 2 dates (your NSTimeInterval) then you can easily convert that into a string in the format days:hours:mins:secs as follows.
- (NSString*)secsToDaysHoursMinutesSecondsString:(NSTimeInterval)theSeconds {
div_t r1 = div(theSeconds, 60*60*24);
NSInteger theDays = r1.quot;
NSInteger secsLeftFromDays = r1.rem;
div_t r2 = div(secsLeftFromDays, 60*60);
NSInteger theHours = r2.quot;
NSInteger secsLeftFromHours = r2.rem;
div_t r3 = div(secsLeftFromHours, 60);
NSInteger theMins = r3.quot;
NSInteger theSecs = r3.rem;
NSString* days;
if (theDays < 10) { // make it 2 digits
days = [NSString stringWithFormat:#"0%i", theDays];
} else {
days = [NSString stringWithFormat:#"%i", theDays];
}
NSString* hours;
if (theHours < 10) { // make it 2 digits
hours = [NSString stringWithFormat:#"0%i", theHours];
} else {
hours = [NSString stringWithFormat:#"%i", theHours];
}
NSString* mins;
if (theMins < 10) { // make it 2 digits
mins = [NSString stringWithFormat:#"0%i", theMins];
} else {
mins = [NSString stringWithFormat:#"%i", theMins];
}
NSString* secs;
if (theSecs < 10) { // make it 2 digits
secs = [NSString stringWithFormat:#"0%i", theSecs];
} else {
secs = [NSString stringWithFormat:#"%i", theSecs];
}
return [NSString stringWithFormat:#"%#:%#:%#:%#", days, hours, mins,secs];
}
//Another simple way to get the numbers of days difference to a future day from today.
NSTimeInterval todaysDiff = [todayDate timeIntervalSinceNow];
NSTimeInterval futureDiff = [futureDate timeIntervalSinceNow];
NSTimeInterval dateDiff = futureDiff - todaysDiff;
div_t r1 = div(dateDiff, 60*60*24);
NSInteger theDays = r1.quot;
label.text = [NSString stringWithFormat:#"%i", theDays];
I have two dates: 2009-05-11 and the current date. I want to check whether the given date is the current date or not. How is this possible.
Cocoa has couple of methods for this:
in NSDate
– isEqualToDate:
– earlierDate:
– laterDate:
– compare:
When you use - (NSComparisonResult)compare:(NSDate *)anotherDate ,you get back one of these:
The receiver and anotherDate are exactly equal to each other, NSOrderedSame
The receiver is later in time than anotherDate, NSOrderedDescending
The receiver is earlier in time than anotherDate, NSOrderedAscending.
example:
NSDate * now = [NSDate date];
NSDate * mile = [[NSDate alloc] initWithString:#"2001-03-24 10:45:32 +0600"];
NSComparisonResult result = [now compare:mile];
NSLog(#"%#", now);
NSLog(#"%#", mile);
switch (result)
{
case NSOrderedAscending: NSLog(#"%# is in future from %#", mile, now); break;
case NSOrderedDescending: NSLog(#"%# is in past from %#", mile, now); break;
case NSOrderedSame: NSLog(#"%# is the same as %#", mile, now); break;
default: NSLog(#"erorr dates %#, %#", mile, now); break;
}
[mile release];
Here buddy. This function will match your date with any specific date and will be able to tell whether they match or not. You can also modify the components to match your requirements.
- (BOOL)isSameDay:(NSDate*)date1 otherDay:(NSDate*)date2 {
NSCalendar* calendar = [NSCalendar currentCalendar];
unsigned unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit;
NSDateComponents* comp1 = [calendar components:unitFlags fromDate:date1];
NSDateComponents* comp2 = [calendar components:unitFlags fromDate:date2];
return [comp1 day] == [comp2 day] &&
[comp1 month] == [comp2 month] &&
[comp1 year] == [comp2 year];}
Regards,
Naveed Butt
NSDate *today = [NSDate date]; // it will give you current date
NSDate *newDate = [NSDate dateWithString:#"xxxxxx"]; // your date
NSComparisonResult result;
//has three possible values: NSOrderedSame,NSOrderedDescending, NSOrderedAscending
result = [today compare:newDate]; // comparing two dates
if(result==NSOrderedAscending)
NSLog(#"today is less");
else if(result==NSOrderedDescending)
NSLog(#"newDate is less");
else
NSLog(#"Both dates are same");
There are other ways that you may use to compare an NSDate objects. Each of the
methods will be more efficient at certain tasks. I have chosen the compare method
because it will handle most of your basic date comparison needs.
This category offers a neat way to compare NSDates:
#import <Foundation/Foundation.h>
#interface NSDate (Compare)
-(BOOL) isLaterThanOrEqualTo:(NSDate*)date;
-(BOOL) isEarlierThanOrEqualTo:(NSDate*)date;
-(BOOL) isLaterThan:(NSDate*)date;
-(BOOL) isEarlierThan:(NSDate*)date;
//- (BOOL)isEqualToDate:(NSDate *)date; already part of the NSDate API
#end
And the implementation:
#import "NSDate+Compare.h"
#implementation NSDate (Compare)
-(BOOL) isLaterThanOrEqualTo:(NSDate*)date {
return !([self compare:date] == NSOrderedAscending);
}
-(BOOL) isEarlierThanOrEqualTo:(NSDate*)date {
return !([self compare:date] == NSOrderedDescending);
}
-(BOOL) isLaterThan:(NSDate*)date {
return ([self compare:date] == NSOrderedDescending);
}
-(BOOL) isEarlierThan:(NSDate*)date {
return ([self compare:date] == NSOrderedAscending);
}
#end
Simple to use:
if([aDateYouWantToCompare isEarlierThanOrEqualTo:[NSDate date]]) // [NSDate date] is now
{
// do your thing ...
}
If you make both dates NSDates you can use NSDate's compare: method:
NSComparisonResult result = [Date2 compare:Date1];
if(result==NSOrderedAscending)
NSLog(#"Date1 is in the future");
else if(result==NSOrderedDescending)
NSLog(#"Date1 is in the past");
else
NSLog(#"Both dates are the same");
You can take a look at the docs here.
By this method also you can compare two dates
NSDate * dateOne = [NSDate date];
NSDate * dateTwo = [NSDate date];
if([dateOne compare:dateTwo] == NSOrderedAscending)
{
}
The best way I found was to check the difference between the given date and today:
NSCalendar* calendar = [NSCalendar currentCalendar];
NSDate* now = [NSDate date];
int differenceInDays =
[calendar ordinalityOfUnit:NSCalendarUnitDay inUnit:NSCalendarUnitEra forDate:date] -
[calendar ordinalityOfUnit:NSCalendarUnitDay inUnit:NSCalendarUnitEra forDate:now];
According to Listing 13 of Calendrical Calculations in Apple's Date and Time Programming Guide [NSCalendar ordinalityOfUnit:NSDayCalendarUnit inUnit: NSEraCalendarUnit forDate:myDate] gives you the number of midnights since the start of the era.
This way it's easy to check whether the date is yesterday, today, or tomorrow.
switch (differenceInDays) {
case -1:
dayString = #"Yesterday";
break;
case 0:
dayString = #"Today";
break;
case 1:
dayString = #"Tomorrow";
break;
default: {
NSDateFormatter* dayFormatter = [[NSDateFormatter alloc] init];
[dayFormatter setLocale:usLocale];
[dayFormatter setDateFormat:#"dd MMM"];
dayString = [dayFormatter stringFromDate: date];
break;
}
}
NSDateFormatter *df= [[NSDateFormatter alloc] init];
[df setDateFormat:#"yyyy-MM-dd"];
NSDate *dt1 = [[NSDate alloc] init];
NSDate *dt2 = [[NSDate alloc] init];
dt1=[df dateFromString:#"2011-02-25"];
dt2=[df dateFromString:#"2011-03-25"];
NSComparisonResult result = [dt1 compare:dt2];
switch (result)
{
case NSOrderedAscending: NSLog(#"%# is greater than %#", dt2, dt1); break;
case NSOrderedDescending: NSLog(#"%# is less %#", dt2, dt1); break;
case NSOrderedSame: NSLog(#"%# is equal to %#", dt2, dt1); break;
default: NSLog(#"erorr dates %#, %#", dt2, dt1); break;
}
Enjoy coding......
In Cocoa, to compare dates, use one of isEqualToDate, compare, laterDate, and earlierDate methods on NSDate objects, instantiated with the dates you need.
Documentation:
http://developer.apple.com/documentation/Cocoa/Reference/Foundation/Classes/NSDate_Class/Reference/Reference.html#//apple_ref/occ/instm/NSDate/isEqualToDate:
http://developer.apple.com/documentation/Cocoa/Reference/Foundation/Classes/NSDate_Class/Reference/Reference.html#//apple_ref/occ/instm/NSDate/earlierDate:
http://developer.apple.com/documentation/Cocoa/Reference/Foundation/Classes/NSDate_Class/Reference/Reference.html#//apple_ref/occ/instm/NSDate/laterDate:
http://developer.apple.com/documentation/Cocoa/Reference/Foundation/Classes/NSDate_Class/Reference/Reference.html#//apple_ref/occ/instm/NSDate/compare:
What you really need is to compare two objects of the same kind.
Create an NSDate out of your string date (#"2009-05-11") :
http://blog.evandavey.com/2008/12/how-to-convert-a-string-to-nsdate.html
If the current date is a string too, make it an NSDate. If its already an NSDate, leave it.
Here's the Swift variant on Pascal's answer:
extension NSDate {
func isLaterThanOrEqualTo(date:NSDate) -> Bool {
return !(self.compare(date) == NSComparisonResult.OrderedAscending)
}
func isEarlierThanOrEqualTo(date:NSDate) -> Bool {
return !(self.compare(date) == NSComparisonResult.OrderedDescending)
}
func isLaterThan(date:NSDate) -> Bool {
return (self.compare(date) == NSComparisonResult.OrderedDescending)
}
func isEarlierThan(date:NSDate) -> Bool {
return (self.compare(date) == NSComparisonResult.OrderedAscending)
}
}
Which can be used as:
self.expireDate.isEarlierThanOrEqualTo(NSDate())
Here's the function from Naveed Rafi's answer converted to Swift if anyone else is looking for it:
func isSameDate(#date1: NSDate, date2: NSDate) -> Bool {
let calendar = NSCalendar()
let date1comp = calendar.components(.YearCalendarUnit | .MonthCalendarUnit | .DayCalendarUnit, fromDate: date1)
let date2comp = calendar.components(.YearCalendarUnit | .MonthCalendarUnit | .DayCalendarUnit, fromDate: date2)
return (date1comp.year == date2comp.year) && (date1comp.month == date2comp.month) && (date1comp.day == date2comp.day)
}
Get Today's Date:
NSDate* date = [NSDate date];
Create a Date From Scratch:
NSDateComponents* comps = [[NSDateComponents alloc]init];
comps.year = 2015;
comps.month = 12;
comps.day = 31;
NSCalendar* calendar = [NSCalendar currentCalendar];
NSDate* date = [calendar dateFromComponents:comps];
Add a day to a Date:
NSDate* date = [NSDate date];
NSDateComponents* comps = [[NSDateComponents alloc]init];
comps.day = 1;
NSCalendar* calendar = [NSCalendar currentCalendar];
NSDate* tomorrow = [calendar dateByAddingComponents:comps toDate:date options:nil];
Subtract a day from a Date:
NSDate* date = [NSDate date];
NSDateComponents* comps = [[NSDateComponents alloc]init];
comps.day = -1;
NSCalendar* calendar = [NSCalendar currentCalendar];
NSDate* yesterday = [calendar dateByAddingComponents:comps toDate:date options:nil];
Convert a Date to a String:
NSDate* date = [NSDate date];
NSDateFormatter* formatter = [[NSDateFormatter alloc]init];
formatter.dateFormat = #"MMMM dd, yyyy";
NSString* dateString = [formatter stringFromDate:date];
Convert a String to a Date:
NSDateFormatter* formatter = [[NSDateFormatter alloc]init];
formatter.dateFormat = #"MMMM dd, yyyy";
NSDate* date = [formatter dateFromString:#"August 02, 2014"];
Find how many days are in a month:
NSDate* date = [NSDate date];
NSCalendar* cal = [NSCalendar currentCalendar];
NSRange currentRange = [cal rangeOfUnit:NSDayCalendarUnit inUnit:NSMonthCalendarUnit forDate:date];
NSInteger numberOfDays = currentRange.length;
Calculate how much time something took:
NSDate* start = [NSDate date];
for(int i = 0; i < 1000000000; i++);
NSDate* end = [NSDate date];
NSTimeInterval duration = [end timeIntervalSinceDate:start];
Find the Day Of Week for a specific Date:
NSDate* date = [NSDate date];
NSCalendar* cal = [NSCalendar currentCalendar];
NSInteger dow = [cal ordinalityOfUnit:NSWeekdayCalendarUnit inUnit:NSWeekCalendarUnit forDate:date];
Then use NSComparisonResult to compare date.
..
NSString *date = #"2009-05-11"
NSString *nowDate = [[[NSDate date]description]substringToIndex: 10];
if([date isEqualToString: nowDate])
{
// your code
}