I am working on an iphone app for class and my group is having some time trouble.
The idea we are working with is that we have a scheduled event (say 2:00pm) and we want to know if we are within a certain amount of time from the scheduled time (say +/- 15 minutes). So for this example if the event was at 2pm, if this event was called from 1:45-2:15pm the method would return true/yes, and otherwise, it would return false/no.
I know how to current time/date, but how do I do the part with checking to see if it is within a certain range of time from the event time?
?
So what I am going for would be a method similar to the following with currentTime getting a NSDate object for the current time and classStartTime getting a NSDate object for the start time of the class:
- (BOOL)dateInRange:(NSDate*)currentTime inRangeOf:(NSDate*)classStartTime
{
if([currentTime <= [classStartTime dateByAddingTimeInterval:60*15]] && [currentTime >= [classStartTime dateByAddingTimeInterval:-(60*15)]])
{
return TRUE;
}
else{
return FALSE;
}
}
I know this doesn't work. How do I get the comparison part of the if statement to work properly
I guess, your time is a NSDate. You could use TimeIntervalSinceDate: with the start time of your interval and check if the result is positive and smaller than your interval length.
Use NSDate and NSDateComponents. I don't have a Mac nearby, so the following code will probably have errors in it.
NSCalendar *gregorian = [[NSCalendar alloc]initWithCalendarIdentifier:NSGregorianCalendar];
int comp = NSHourCalendarUnit | NSMinuteCalendarUnit;
NSDateComponents *theDateComponents = [gregorian components:comp fromDate:[NSDate date]];
int hour = [theDateComponents hour];
int minute = [theDateComponents minute];
if ((hour == 13 && minute >= 45) || (hour == 14 && minute <= 15)) {
//do your stuff
}
Hope it helps
Find a start date and and end date with
+ (id)dateWithTimeInterval:(NSTimeInterval)seconds sinceDate:(NSDate *)date
then use the compare method to check that the date you are checking falls within your dates...
Related
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Determine if current local time is between two times (ignoring the date portion)
In iOS, how can I do the following:
I have two NSDate objects that represent the opening and closing times for a store. The times within these objects are accurate but the date is unspecified (the store opens and closes at the same time regardless of the date). How can I check if the current time falls between in this time frame?
Note, if it would help for the opening and closing times to be in another format other than NSDate objects, I'm fine with that. Currently, I'm just reading in a date string such as "12:30" from a file and using date formatter to create a matching NSDate object.
Update: Note that this solution is specific to your case and assumes that store opening hours don't span two days. For example it won't work if the opening hour goes from Monday 9pm to Tuesday 10am. Since 10pm is after 9pm but not before 10am (within a day). So keep that in mind.
I cooked up a function which will tell you if the time of one date is between two other dates (it ignores the year, month and day). There's also a second helper function which gives you a new NSDate with the year, month and day components "neutralized" (eg. set to some static value).
The idea is to set the year, month and day components to be the same between all dates so that the comparison will only rely on the time.
I'm not sure if it's the most efficient approach, but it works.
- (NSDate *)dateByNeutralizingDateComponentsOfDate:(NSDate *)originalDate {
NSCalendar *gregorian = [[[NSCalendar alloc]
initWithCalendarIdentifier:NSGregorianCalendar] autorelease];
// Get the components for this date
NSDateComponents *components = [gregorian components: (NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit) fromDate: originalDate];
// Set the year, month and day to some values (the values are arbitrary)
[components setYear:2000];
[components setMonth:1];
[components setDay:1];
return [gregorian dateFromComponents:components];
}
- (BOOL)isTimeOfDate:(NSDate *)targetDate betweenStartDate:(NSDate *)startDate andEndDate:(NSDate *)endDate {
if (!targetDate || !startDate || !endDate) {
return NO;
}
// Make sure all the dates have the same date component.
NSDate *newStartDate = [self dateByNeutralizingDateComponentsOfDate:startDate];
NSDate *newEndDate = [self dateByNeutralizingDateComponentsOfDate:endDate];
NSDate *newTargetDate = [self dateByNeutralizingDateComponentsOfDate:targetDate];
// Compare the target with the start and end dates
NSComparisonResult compareTargetToStart = [newTargetDate compare:newStartDate];
NSComparisonResult compareTargetToEnd = [newTargetDate compare:newEndDate];
return (compareTargetToStart == NSOrderedDescending && compareTargetToEnd == NSOrderedAscending);
}
I used this code to test it. You can see that the year, month and days are set to some random values and don't affect the time checking.
NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
[dateFormatter setDateFormat:#"yyyy:MM:dd HH:mm:ss"];
NSDate *openingDate = [dateFormatter dateFromString:#"2012:03:12 12:30:12"];
NSDate *closingDate = [dateFormatter dateFromString:#"1983:11:01 17:12:00"];
NSDate *targetDate = [dateFormatter dateFromString:#"2034:09:24 14:15:54"];
if ([self isTimeOfDate:targetDate betweenStartDate:openingDate andEndDate:closingDate]) {
NSLog(#"TARGET IS INSIDE!");
}else {
NSLog(#"TARGET IS NOT INSIDE!");
}
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
How can I calculate the difference between two dates?
NSDate, comparing two dates
I have got two dates. How to check if theres a difference of 30 days in between them?
I actually have an In-App purchase which needs to be disabled after every 30-days of purchase.
When the user buys the feature, the Date is saved and so I need to check the dates. If 30-days have passed, I need to disable the feature again.
You can convert both dates to seconds with timeIntervalSince1970 and then check if difference is bigger than 2592000 (30*24*60*60 which is 30 days * 24 hours * 60 minutes * 60 seconds).
NSTimeInterval difference = [date1 timeIntervalSince1970] - [date2 timeIntervalSince1970];
if(difference >2592000)
{
//do your stuff here
}
EDIT:
For more compact version you can use - (NSTimeInterval)timeIntervalSinceDate:(NSDate *)anotherDate
NSTimeInterval difference = [date1 timeIntervalSinceDate:date2];
if(difference >2592000)
{
//do your stuff here
}
Provide the start and end NSDate in following manner:
NSDate *date_Start;
NSDate *date_End;
NSCalendar *cal=[NSCalendar currentCalendar];
NSDateComponents *components=[cal components:NSDayCalendarUnit fromDate:date_Start toDate:date_End options:0];
int days=[components day];
if(days>30){
//Your code here
}
You could create a date which is +30days from now :
NSDate *thrityDaysPlus = [[NSDate date] dateByAddingTimeInterval:3600*24*30]
and then simply compare it to your saved date
if ([date1 compare:date2] == NSOrderedDescending) {
NSLog(#"date1 is later than date2");
} else if ([date1 compare:date2] == NSOrderedAscending) {
NSLog(#"date1 is earlier than date2");
} else {
NSLog(#"dates are the same");
}
So, I'm having a difficult time (no pun intended) finding if an NSDate is within a specific range. Consider this: a scheduled visit between 5:00 PM and 6:00 PM. I want to find if the scheduled visit is within +/- 15 minutes of the current time. Thus my safe range is 4:45 PM to 6:15 PM. How can I find out if the scheduled visit is in or out of the range? Here's the code I've got so far, which doesn't work at all...
- (BOOL)isInScheduledRange {
// NSLog(#"Start: %f", [self.start timeIntervalSinceNow]);
// NSLog(#"End: %f", [self.end timeIntervalSinceNow]);
//
// if (([self.start timeIntervalSinceNow] >= -900) && ([self.end timeIntervalSinceNow] <= 3600)) {
// NSLog(#"In Range");
//
// return YES;
// }
//
NSDate *now = [[NSDate alloc] init];
// if ((([self.start timeIntervalSinceDate:now] >= -900) && ([self.start timeIntervalSinceDate:now] <= 900)) && (([self.end timeIntervalSinceDate:now] <= -900) && ([self.end timeIntervalSinceDate:now] >= 900))) {
// NSLog(#"In Range");
// }
NSLog(#"%#; %#; %#", now, self.start, self.end);
// NSLog(#"%#; %#", [self.start timeIntervalSinceDate:now], [self.end timeIntervalSinceDate:now]);
if ((([self.start timeIntervalSinceDate:now] >= -900) && ([self.start timeIntervalSinceDate:now] <= 0)) && (([self.end timeIntervalSinceDate:now] >= 0) && ([self.end timeIntervalSinceDate:now] <= 900))) {
NSLog(#"In Range");
}
return NO;
[now release];
}
I'd appreciate some help. I'm having difficulties with this time calculation.
On a separate note, I hate dealing with time no matter what platform I'm working with...
You want to check if the start time is less than 900 seconds after the current time, and the end time is less than 900 seconds before the current time. timeIntervalSinceDate: returns a positive number if the object it is called on is after the argument, you need to check for start <= 900 and end >= −900. Also, you could simplify your code by using timeIntervalSinceNow instead of manually getting the current date and passing it to timeIntervalSinceDate:. Finally, if you can assume (or previously ensured) that the start is before the end, then you don't need the two middle tests, as they will both have to be true for both of the others to be true.
if([self.start timeIntervalSinceNow] <= 900 && [self.end timeIntervalSinceNow] >= −900) {
NSLog(#"In range")
}
Here's some verbose (and silly) code that explains my approach to this problem
NSTimeInterval secondsBeforeStart = [self.start timeIntervalSinceNow];
if ( secondsBeforeStart > (15 * 60))
{
// The result for '[self.start timeIntervalSinceNow]' is positive as long
// as 'self.start' remains in the future. We're not in range until there
// are 900 seconds to go or less.
NSLog( #"Still time to chill.");
// More than fifteen minutes to go so return NO.
return NO;
}
else
{
NSLog( #"OMG did I miss it!!!");
NSTimeInterval secondsBeforeEnd = [self.end timeIntervalSinceNow];
if ( secondsBeforeEnd < -( 15 * 60))
{
// The result for '[self.end timeIntervalSinceNow]' is negative when
// 'self.end' is in the past.
// It's been more than 900 seconds since the end of the appointment
// so we've missed it.
NSLog( #"Ahhhhh!!!");
// More than 900 seconds past the end of the event so return NO.
return NO;
}
else
{
// We are somewhere between 900 seconds before the start and
// 900 seconds before the end so we are golden.
NSLog( #"Whew, we made it.");
return YES;
}
}
The way I would have coded it would have been
BOOL inRange = NO; // Assume we are not in the proper time range.
if ( [self.start timeIntervalSinceNow] <= ( 15 * 60))
{
// 'Now' is at least 900 seconds before the start time but could be later.
if ( [self.end timeIntervalSinceNow] >= -( 15 * 60))
{
// 'Now' is not yet 900 seconds past the end time.
inRange = YES
}
}
return inRange;
Note: I haven't actually compiled this but I'm pretty sure the logic is correct.
Finally, you did notice that your last two lines
return NO;
[now release];
}
would have created a memory leak. (Release and then return ;^))
This is a distance problem - you want to know if the current time is within 900 seconds of the target time. Compute distance problems by taking the absolute value of the difference between the two points. By taking the absolute value of the difference, the order of the two samples doesn't matter.
/**
* #brief Return YES if the current time is within 900 seconds of the meeting time (NSDate* time).
*/
-(BOOL)currentTimeIsWithin900SecondsOf:(NSDate*)time
{
NSDate* now = [NSDate date];
return fabs( [now timeIntervalSinceReferenceDate] - [time timeIntervalSinceReferenceDate] ) < 900;
}
You need to create three NSDates. Then convert NSDates to time intervals using intervalSinceReferenceDate and compare those. You manually set up NSDates by using NSDateComponents.
I must be missing something small her but can't figure it out. Trying to create a date for comparison, but I can't seem to offset currentDate from GMT to EST:
// current date (gmt) //
NSDate *currentDate = [NSDate date];
NSTimeZone *currentDateTimeZone = [NSTimeZone timeZoneWithAbbreviation:#"EST"];
NSDateFormatter *currentDateFormat = [[NSDateFormatter alloc]init];
[currentDateFormat setTimeZone:currentDateTimeZone];
[currentDateFormat setDateFormat:#"yyyy-MM-dd HH:mm:ss zzz"];
NSString *currentDateString = [currentDateFormat stringFromDate:currentDate];
NSLog(#"currentDateString: %#", currentDateString); // returns 2011-01-05 13:30:30 EST
NSDate *currentDateWithOffset = [currentDateFormat dateFromString:currentDateString];
NSLog(#"currentDateWithOffset: %#", currentDateWithOffset); // returns 2011-01-05 18:30:30 +0000
Thanks!
Edit:
I'm calling a method in a separate class (trying to make this portable) using the following line:
[Expiration expires:[[NSDate alloc] initWithString:#"2011-01-07 12:00:00 +0000"] within:1.0]
in the expires method, I have these lines:
NSComparisonResult comparison = [currentDateWithOffset compare:expires]; // check for a fixed date to disable the demo
double withinRange = [installDate timeIntervalSinceDate:currentDateWithOffset]; // check for number of seconds between "within" and the install date
I'm then comparing these two values like so:
if(withinRange >= within && withinRange > 0.0) {
// app is expired //
}
else {
// app is still enabled (so far...) //
if(comparison == NSOrderedDescending || comparison == NSOrderedSame) {
// app is expired //
}
else {
// app is still enabled //
}
}
Does this help? Thanks for your patience!
Edit:
Here's the entire expires:within method as it currently stands...
+(BOOL)expire:(NSDate*)expires within:(double)within {
// default expired value //
BOOL expired = NO;
// convert within value from days to seconds //
within *= 24.0 * 60.0 * 60.0;
// current date (gmt) //
NSDate *currentDate = [NSDate date];
// install date //
NSDate *installDate = [[NSUserDefaults standardUserDefaults]objectForKey:#"installDate"];
// check for a value in installDate //
if (nil == installDate) {
// app is running for the first time //
[[NSUserDefaults standardUserDefaults]setObject:currentDate forKey:#"installDate"];
[[NSUserDefaults standardUserDefaults]synchronize];
installDate = currentDate;
}
if([installDate timeIntervalSinceNow] < (-within)) {
expired = YES;
}
else {
if([expires timeIntervalSinceNow] < 0) {
expired = YES;
}
}
NSLog(#"installDate:%#", installDate);
NSLog(#"expires:%#", expires);
NSLog(#"currentDate:%#", currentDate);
return expired;
}
I'm then calling it from another class with
message.text = (YES == [Expiration expire:[[NSDate alloc] initWithString:#"2011-01-07 12:00:00 -0500"] within:(0.015625/2)]) ? #"This App is Expired" : #"This App is Active";
When running in the simulator (fresh app install), NSLog displayed this...
[Session started at 2011-01-06 10:43:46 -0500.]
2011-01-06 10:43:48.146 TimeBasedDemo[14717:207] installDate:2011-01-06 15:43:48 +0000
2011-01-06 10:43:48.147 TimeBasedDemo[14717:207] expires:2011-01-07 17:00:00 +0000
2011-01-06 10:43:48.147 TimeBasedDemo[14717:207] currentDate:2011-01-06 15:43:48 +0000
None of these answers gave me an NSDate object with the current, local date. So here's how I did it:
NSDate *currentDateWithOffset = [NSDate dateWithTimeIntervalSinceNow:[[NSTimeZone localTimeZone] secondsFromGMT]];
An NSDate object represents an instant in time irrespective of time zone and calendar considerations. Time zone info is relevant when you print or parse a date, but it is not stored within the NSDate.
Say you are creating your expiration date like this:
NSDate *exp=[[NSDate alloc] initWithString:#"2011-01-07 12:00:00 +0000"]
That says you want the expiration to occur at noon GMT, on the 7th Jan. If you want it to expire at noon EST, create it with -0500 instead. What you should not have to do is mess with the current time when you do a comparison.
An easy way just to see if the time has passed is then
if ([exp timeIntervalSinceNow]<0) { /* it's expired */ }
and you can see if within seconds have passed since the install date like this:
if ([installDate timeIntervalSinceNow]<(-within)]) { /* it's expired */}
In Cocoa, NSDate is an abstract representation of a date with no time zone information applied. Note that currentDateWithOffset is the same date as the date string, just in a different time zone (five hours ahead). This is expected behavior, as NSDate does not persist the time zone used to create it.
I tinkered around a bit more and found a way to 'cheat' the offset to suit my needs. From other reading, I'm guessing that NSCalendar might be a better long term-solution, but for now I ended up changing
NSDate *currentDateWithOffset = [currentDateFormat dateFromString:currentDateString];
to
NSDate *currentDateWithOffset = [[NSDate alloc] initWithString:[NSString stringWithFormat:#"%# +0000", currentDateString]];
That got me the results I needed and works in the later comparisons I'm using. Thanks for the background info all!
I've got an amount of seconds that passed from a certain event. It's stored in a NSTimeInterval data type.
I want to convert it into minutes and seconds.
For example I have: "326.4" seconds and I want to convert it into the following string:
"5:26".
What is the best way to achieve this goal?
Thanks.
Brief Description
The answer from Brian Ramsay is more convenient if you only want to convert to minutes.
If you want Cocoa API do it for you and convert your NSTimeInterval not only to minutes but also to days, months, week, etc,... I think this is a more generic approach
Use NSCalendar method:
(NSDateComponents *)components:(NSUInteger)unitFlags fromDate:(NSDate *)startingDate toDate:(NSDate *)resultDate options:(NSUInteger)opts
"Returns, as an NSDateComponents object using specified components, the difference between two supplied dates". From the API documentation.
Create 2 NSDate whose difference is the NSTimeInterval you want to convert. (If your NSTimeInterval comes from comparing 2 NSDate you don't need to do this step, and you don't even need the NSTimeInterval).
Get your quotes from NSDateComponents
Sample Code
// The time interval
NSTimeInterval theTimeInterval = 326.4;
// Get the system calendar
NSCalendar *sysCalendar = [NSCalendar currentCalendar];
// Create the NSDates
NSDate *date1 = [[NSDate alloc] init];
NSDate *date2 = [[NSDate alloc] initWithTimeInterval:theTimeInterval sinceDate:date1];
// Get conversion to months, days, hours, minutes
unsigned int unitFlags = NSHourCalendarUnit | NSMinuteCalendarUnit | NSDayCalendarUnit | NSMonthCalendarUnit;
NSDateComponents *conversionInfo = [sysCalendar components:unitFlags fromDate:date1 toDate:date2 options:0];
NSLog(#"Conversion: %dmin %dhours %ddays %dmoths",[conversionInfo minute], [conversionInfo hour], [conversionInfo day], [conversionInfo month]);
[date1 release];
[date2 release];
Known issues
Too much for just a conversion, you are right, but that's how the API works.
My suggestion: if you get used to manage your time data using NSDate and NSCalendar, the API will do the hard work for you.
pseudo-code:
minutes = floor(326.4/60)
seconds = round(326.4 - minutes * 60)
All of these look more complicated than they need to be! Here is a short and sweet way to convert a time interval into hours, minutes and seconds:
NSTimeInterval timeInterval = 326.4;
long seconds = lroundf(timeInterval); // Since modulo operator (%) below needs int or long
int hour = seconds / 3600;
int mins = (seconds % 3600) / 60;
int secs = seconds % 60;
Note when you put a float into an int, you get floor() automatically, but you can add it to the first two if if makes you feel better :-)
Forgive me for being a Stack virgin... I'm not sure how to reply to Brian Ramsay's answer...
Using round will not work for second values between 59.5 and 59.99999. The second value will be 60 during this period. Use trunc instead...
double progress;
int minutes = floor(progress/60);
int seconds = trunc(progress - minutes * 60);
If you're targeting at or above iOS 8 or OS X 10.10, this just got a lot easier. The new NSDateComponentsFormatter class allows you to convert a given NSTimeInterval from its value in seconds to a localized string to show the user. For example:
Objective-C
NSTimeInterval interval = 326.4;
NSDateComponentsFormatter *componentFormatter = [[NSDateComponentsFormatter alloc] init];
componentFormatter.unitsStyle = NSDateComponentsFormatterUnitsStylePositional;
componentFormatter.zeroFormattingBehavior = NSDateComponentsFormatterZeroFormattingBehaviorDropAll;
NSString *formattedString = [componentFormatter stringFromTimeInterval:interval];
NSLog(#"%#",formattedString); // 5:26
Swift
let interval = 326.4
let componentFormatter = NSDateComponentsFormatter()
componentFormatter.unitsStyle = .Positional
componentFormatter.zeroFormattingBehavior = .DropAll
if let formattedString = componentFormatter.stringFromTimeInterval(interval) {
print(formattedString) // 5:26
}
NSDateCompnentsFormatter also allows for this output to be in longer forms. More info can be found in NSHipster's NSFormatter article. And depending on what classes you're already working with (if not NSTimeInterval), it may be more convenient to pass the formatter an instance of NSDateComponents, or two NSDate objects, which can be done as well via the following methods.
Objective-C
NSString *formattedString = [componentFormatter stringFromDate:<#(NSDate *)#> toDate:<#(NSDate *)#>];
NSString *formattedString = [componentFormatter stringFromDateComponents:<#(NSDateComponents *)#>];
Swift
if let formattedString = componentFormatter.stringFromDate(<#T##startDate: NSDate##NSDate#>, toDate: <#T##NSDate#>) {
// ...
}
if let formattedString = componentFormatter.stringFromDateComponents(<#T##components: NSDateComponents##NSDateComponents#>) {
// ...
}
Brian Ramsay’s code, de-pseudofied:
- (NSString*)formattedStringForDuration:(NSTimeInterval)duration
{
NSInteger minutes = floor(duration/60);
NSInteger seconds = round(duration - minutes * 60);
return [NSString stringWithFormat:#"%d:%02d", minutes, seconds];
}
Here's a Swift version:
func durationsBySecond(seconds s: Int) -> (days:Int,hours:Int,minutes:Int,seconds:Int) {
return (s / (24 * 3600),(s % (24 * 3600)) / 3600, s % 3600 / 60, s % 60)
}
Can be used like this:
let (d,h,m,s) = durationsBySecond(seconds: duration)
println("time left: \(d) days \(h) hours \(m) minutes \(s) seconds")
NSDate *timeLater = [NSDate dateWithTimeIntervalSinceNow:60*90];
NSTimeInterval duration = [timeLater timeIntervalSinceNow];
NSInteger hours = floor(duration/(60*60));
NSInteger minutes = floor((duration/60) - hours * 60);
NSInteger seconds = floor(duration - (minutes * 60) - (hours * 60 * 60));
NSLog(#"timeLater: %#", [dateFormatter stringFromDate:timeLater]);
NSLog(#"time left: %d hours %d minutes %d seconds", hours,minutes,seconds);
Outputs:
timeLater: 22:27
timeLeft: 1 hours 29 minutes 59 seconds
Since it's essentially a double...
Divide by 60.0 and extract the integral part and the fractional part.
The integral part will be the whole number of minutes.
Multiply the fractional part by 60.0 again.
The result will be the remaining seconds.
Remember that the original question is about a string output, not pseudo-code or individual string components.
I want to convert it into the following string: "5:26"
Many answers are missing the internationalization issues, and most doing the math computations by hand. All just so 20th century...
Do not do the Math yourself (Swift 4)
let timeInterval: TimeInterval = 326.4
let dateComponentsFormatter = DateComponentsFormatter()
dateComponentsFormatter.unitsStyle = .positional
if let formatted = dateComponentsFormatter.string(from: timeInterval) {
print(formatted)
}
5:26
Leverage on libraries
If you really want individual components, and pleasantly readable code, check out SwiftDate:
import SwiftDate
...
if let minutes = Int(timeInterval).seconds.in(.minute) {
print("\(minutes)")
}
5
Credits to #mickmaccallum and #polarwar for adequate usage of DateComponentsFormatter
How I did this in Swift (including the string formatting to show it as "01:23"):
let totalSeconds: Double = someTimeInterval
let minutes = Int(floor(totalSeconds / 60))
let seconds = Int(round(totalSeconds % 60))
let timeString = String(format: "%02d:%02d", minutes, seconds)
NSLog(timeString)
Swift 2 version
extension NSTimeInterval {
func toMM_SS() -> String {
let interval = self
let componentFormatter = NSDateComponentsFormatter()
componentFormatter.unitsStyle = .Positional
componentFormatter.zeroFormattingBehavior = .Pad
componentFormatter.allowedUnits = [.Minute, .Second]
return componentFormatter.stringFromTimeInterval(interval) ?? ""
}
}
let duration = 326.4.toMM_SS()
print(duration) //"5:26"