I tried the following code, but I do not get a condition where the date is in next week. How will I know that the date which is parameter in the function falls in next week? Following code always returns 1.
- (NSInteger)thisW:(NSDate *)date
{
NSCalendar *gregorian = [[NSCalendar alloc]
initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *todaysComponents =
[gregorian components:NSYearCalendarUnit fromDate:[NSDate date]];
NSUInteger todaysWeek = [todaysComponents weekOfYear];
NSDateComponents *otherComponents =
[gregorian components:NSYearCalendarUnit fromDate:date];
NSUInteger datesWeek = [otherComponents weekOfYear];
//NSLog(#"Date %#",date);
if(todaysWeek==datesWeek){
//NSLog(#"Date is in this week");
return 1;
}else if(todaysWeek+1==datesWeek){
//NSLog(#"Date is in next week");
return 2;
} else {
return 0;
}
}
You need to pass NSCalendarUnitWeekOfYear when extracting date components:
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *todaysComponents = [gregorian components:NSCalendarUnitWeekOfYear fromDate:[NSDate date]];
NSUInteger todaysWeek = [todaysComponents weekOfYear];
NSDateComponents *otherComponents = [gregorian NSCalendarUnitWeekOfYear fromDate:date];
NSUInteger datesWeek = [otherComponents weekOfYear];
Using datecomponents for week calculations will give you problems when the dates are close to year's end, i.e. "The first week of the year is designated to be the week containing the first Thursday of the year.(ISO 8601)"
I find it easier to compare dates with certain granularity, weekly in this case (the following code detects if a date is more than one week in the past, last week, this week, next week or further in the future)
-(EventWeekRange)numberOfWeeksFromTodayToEvent:(NSDate *)eventDate {
NSCalendar *calendar = [NSCalendar currentCalendar];
NSComparisonResult comparison = [calendar compareDate:[NSDate date] toDate:eventDate toUnitGranularity:NSCalendarUnitWeekOfYear];
if (comparison == NSOrderedSame) {
return RangeThisWeek;
} else if (comparison == NSOrderedAscending) { // The event date is in the future
// Advance today's date one week to check if this new date is in the same week as the event
NSDate *todaysNextWeek = [[NSDate date]dateByAddingTimeInterval:60*60*24*7];
if ([calendar compareDate:todaysNextWeek toDate:eventDate toUnitGranularity:NSCalendarUnitWeekOfYear] == NSOrderedSame) {
return RangeNextWeek;
} else {
return RangeLater;
}
} else { // The event date is in the past
// Advance the event's date one week to check if this new date is in the same week as today
NSDate *eventsNextWeek = [eventDate dateByAddingTimeInterval:60*60*24*7];
if ([calendar compareDate:eventsNextWeek toDate:[NSDate date] toUnitGranularity:NSCalendarUnitWeekOfYear] == NSOrderedSame) {
return RangeLastWeek;
} else {
return RangeEarlier;
}
}
}
I new in cocoa programing and I want to know how I get the number of working days between to dates. So only from Monday to Friday. Thanks.
NSDate *startDate = ...;
NSDate *stopDate = ...;
NSDateFormatter *df = [NSDateFormatter new];
df.dateFormat = #"yyyy-MM-dd";
startDate = [df dateFromString:[df stringFromDate:startDate]]; // get start of the day
NSDateComponents *comps = [NSDateComponents new];
comps.day = 1; // one day in NSDateComponents
NSUInteger count = 0;
while ([stopDate timeIntervalSinceDate:startDate] >= 0) {
NSInteger weekday = [[NSCalendar currentCalendar] components:NSCalendarUnitWeekday fromDate:startDate].weekday;
if (weekday != 1 && weekday != 6) ++count; // filter out weekend days - 6 and 1
startDate = [[NSCalendar currentCalendar] dateByAddingComponents:comps toDate:startDate options:0]; // increment start day
}
I need Objective C method for converting Gregorian date to Julian days same as this PHP method (GregorianToJD).
Precision: Incorporating time of day in Julian Date conversions
These Julian date conversion methods yield results identical to the U.S. Naval Observatory Online Julian Date Converter, which is more precise than NSDateFormatter's Julian Date conversion. Specifically, the functions below incorporate time-of-day (e.g. hour, minute and seconds), whereas NSDateFormatter rounds to noon GMT.
Swift examples:
func jdFromDate(date : NSDate) -> Double {
let JD_JAN_1_1970_0000GMT = 2440587.5
return JD_JAN_1_1970_0000GMT + date.timeIntervalSince1970 / 86400
}
func dateFromJd(jd : Double) -> NSDate {
let JD_JAN_1_1970_0000GMT = 2440587.5
return NSDate(timeIntervalSince1970: (jd - JD_JAN_1_1970_0000GMT) * 86400)
}
Objective-C examples:
double jdFromDate(NSDate *date) {
double JD_JAN_1_1970_0000GMT = 2440587.5;
return JD_JAN_1_1970_0000GMT + date.timeIntervalSince1970 / 86400;
}
NSDate dataFromJd(double jd) {
double JD_JAN_1_1970_0000GMT = 2440587.5;
return [[NSDate alloc] initWithTimeIntervalSince1970: (jd - JD_JAN_1_1970_0000GMT) * 86400)];
}
Note: Research confirms that the accepted answer rounds the date to a 24-hour interval because it uses the g format-specifier of NSDateFormatter, which returns the Modified Julian Day, according to the UNICODE standard's Date Format Patterns that Apple's date formatting APIs adhere to (according to the Date Formatting Guide).
According to http://en.wikipedia.org/wiki/Julian_day, the Julian day number for January 1, 2000, was 2,451,545. So you can compute the number of days between your date and this
reference date. For example (Jan 1, 2014):
NSUInteger julianDayFor01012000 = 2451545;
NSCalendar *cal = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
[cal setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
NSDateComponents *comp = [[NSDateComponents alloc] init];
comp.year = 2014;
comp.month = 1;
comp.day = 1;
NSDate *date = [cal dateFromComponents:comp];
comp.year = 2000;
comp.month = 1;
comp.day = 1;
NSDate *ref = [cal dateFromComponents:comp];
NSDateComponents *diff = [cal components:NSDayCalendarUnit fromDate:ref toDate:date options:0];
NSInteger julianDays = diff.day + julianDayFor01012000;
NSLog(#"%ld", (long)julianDays);
// Output: 2456659
This gives the same result as http://www.php.net/manual/en/function.gregoriantojd.php:
<?php
$jd = GregorianToJD(1, 1, 2014);
echo "$jd\n";
?>
Inverse direction (Julian days to Gregorian year/month/day):
NSInteger julianDays = 2456659; // From above example
NSUInteger julianDayFor01012000 = 2451545;
NSCalendar *cal = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
[cal setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
NSDateComponents *comp = [[NSDateComponents alloc] init];
comp.year = 2000;
comp.month = 1;
comp.day = 1;
NSDate *ref = [cal dateFromComponents:comp];
NSDateComponents *diff = [[NSDateComponents alloc] init];
diff.day = julianDays - julianDayFor01012000;
NSDate *date = [cal dateByAddingComponents:diff toDate:ref options:0];
comp = [cal components:NSDayCalendarUnit|NSMonthCalendarUnit|NSYearCalendarUnit fromDate:date];
NSLog(#"%04ld-%02ld-%02ld", (long)comp.year, (long)comp.month, (long)comp.day);
// Output: 2014-01-01
UPDATE: As Hot Licks correctly stated in a comment, it is easier to use a date
formatter with the "g" format:
NSCalendar *cal = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *comp = [[NSDateComponents alloc] init];
comp.year = 2014;
comp.month = 1;
comp.day = 1;
NSDate *date = [cal dateFromComponents:comp];
NSDateFormatter *fmt = [[NSDateFormatter alloc] init];
[fmt setDateFormat:#"g"];
NSInteger julianDays = [[fmt stringFromDate:date] integerValue];
NSLog(#"%ld", (long)julianDays);
// Output: 2456659
And for the inverse direction:
NSInteger julianDays = 2456659;
NSDateFormatter *fmt = [[NSDateFormatter alloc] init];
[fmt setDateFormat:#"g"];
NSDate *date = [fmt dateFromString:[#(julianDays) stringValue]];
NSCalendar *cal = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *comp = [cal components:NSDayCalendarUnit|NSMonthCalendarUnit|NSYearCalendarUnit fromDate:date];
NSLog(#"%04ld-%02ld-%02ld", (long)comp.year, (long)comp.month, (long)comp.day);
// Output: 2014-01-01
let date = Date() // now
let cal = Calendar.current
var day = 0
day = cal.ordinality(of: .day, in: .year, for: date) ?? 0
I have this category added to NSDate:
- (bool)isWeekend
{
NSString* s = [self asString:#"e"];
if ([s isEqual:#"6"])
return YES;
else if ([s isEqual:#"7"])
return YES;
else
return NO;
}
Helper function:
- (NSString*)asString:(NSString*)format
{
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:format];
NSString *formattedDateString = [dateFormatter stringFromDate:self];
[dateFormatter release];
return formattedDateString;
}
isWeekend should return YES if it is a saturday or a sunday. But it does not work if the locale has a week start on a sunday, in which case friday will be day 6 and saturday will be day 7.
How can I solve this?
You want to use NSCalendar and NSDateComponents:
NSDate *aDate = [NSDate date];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSRange weekdayRange = [calendar maximumRangeOfUnit:NSWeekdayCalendarUnit];
NSDateComponents *components = [calendar components:NSWeekdayCalendarUnit fromDate:aDate];
NSUInteger weekdayOfDate = [components weekday];
if (weekdayOfDate == weekdayRange.location || weekdayOfDate == weekdayRange.length) {
//the date falls somewhere on the first or last days of the week
NSLog(#"weekend!");
}
This is operating under the assumption that the first and last days of the week comprise the "week ends" (which is true for the Gregorian calendar. It may not be true in other calendars).
As of iOS 8, you can use isDateOnWeekend: on NSCalendar.
In Swift 3+:
extension Date {
var isWeekend: Bool {
return NSCalendar(calendarIdentifier: NSCalendar.Identifier.gregorian)!.isDateInWeekend(self)
}
}
In Swift:
func isWeekend(date: NSDate) -> Bool {
let calendar = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)!
return calendar.isDateInWeekend(date)
}
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
}