different date range for ios versions - ios

when calling method for simulator
version 6.1 it shows:
year---2012
week no---52
weekday---2
resultdate---2012-12-16 18:30:00 +0000
date time is 17 Dec 2012 To 23 Dec 2012
version 5.0 it shows:
year---2012
week no---52
weekday---2
resultdate---2012-12-23 18:30:00 +0000
date time is 24 dec. 2012 To 30 dec. 2012
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
gregorian.Locale = [NSLocale currentLocale];
//[gregorian setTimeZone:[NSTimeZone timeZoneWithName:#"GMT"]];
gregorian.firstWeekday = 2; // Sunday = 1, Saturday = 7
NSDateComponents *components = [gregorian components:NSYearForWeekOfYearCalendarUnit |NSWeekOfYearCalendarUnit |NSWeekdayOrdinalCalendarUnit fromDate:[NSDate date]];
[components setYearForWeekOfYear:2012];
[components setWeekOfYear:52];
[components setWeekdayOrdinal:2];
NSLog(#"year---%ld",(long)[components yearForWeekOfYear]);
NSLog(#"week no---%ld",(long)[components weekOfYear]);
NSLog(#"weekday---%ld",(long)[components weekdayOrdinal]);
NSDate *resultDate = [gregorian dateFromComponents:components];
NSLog(#"resultdate---%#",resultDate);
NSDate *startOfTheWeek;
NSDate *endOfWeek;
NSTimeInterval interval;
[gregorian rangeOfUnit:NSWeekOfYearCalendarUnit startDate:&startOfTheWeek interval:&interval forDate:resultDate];
endOfWeek = [startOfTheWeek dateByAddingTimeInterval:interval-1];
and to get the out put dateformatter used is
NSDateFormatter* dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"dd MMM yyyy"];
NSString *str_StartOfTheWeek = [dateFormatter stringFromDate:startOfTheWeek];
NSString *str_EndOfWeek = [dateFormatter stringFromDate:endOfWeek];
NSLog(#"date time is %#",[NSString stringWithFormat:#"%# To %#",str_StartOfTheWeek,str_EndOfWeek]);
return [NSString stringWithFormat:#"%# To %#",str_StartOfTheWeek,str_EndOfWeek];
how to solve this issue pls help.

To set a weekday (e.g. 2 = Monday) you have to use the NSWeekdayCalendarUnit and setWeekday:, not NSWeekdayOrdinalCalendarUnit and setWeekdayOrdinal::
NSDateComponents *components = [gregorian components:NSYearForWeekOfYearCalendarUnit|NSWeekOfYearCalendarUnit|NSWeekdayCalendarUnit
fromDate:[NSDate date]];
[components setYearForWeekOfYear:2012];
[components setWeekOfYear:52];
[components setWeekday:2];
With this modification, the output is
date time is 17 Dec 2012 To 23 Dec 2012
on both iOS 5 and iOS 6.

Related

Strange NSDate after changing hour

I want to change hour in NSDate. I did something like this:
NSDate *final = [gregorian dateBySettingUnit:NSCalendarUnitHour value:hour.intValue ofDate:self.dateForNewEvent options:NSCalendarMatchStrictly];
where self.dateForNewEvent = 2018-07-09 07:24:13 +0000
and hour.intValue = 5 and i expect date = 2018-07-09 05:00:00 + 0000 but i got 2018-07-10 03:00:00 UTC. How should I do it to get expected date ?
To change the hours of a specific NSDate, you need to manipulate it via NSDateComponents. Please try below code for the same:
NSDate *now = [NSDate date]; // YOUR DATE INSTANCE
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier: NSCalendarIdentifierGregorian];
NSDateComponents *components = [calendar components:NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitDay|NSCalendarUnitHour|NSCalendarUnitMinute|NSCalendarUnitSecond fromDate:now];
[components setHour:5];
NSDate *today5am = [calendar dateFromComponents:components];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
[dateFormatter setDateStyle:NSDateFormatterMediumStyle];
[dateFormatter setTimeStyle:NSDateFormatterMediumStyle];
NSLog(#"Date ===>>> %#",[dateFormatter stringFromDate:[NSDate date]]);
Hope this helps!
I think you are mixing NSDate with NSCalendar: NSDate is a point in time, internally represented in UTC. To get the local date/time as it is displayed on a calendar or watch , you use NSCalendar.
So if you are in MEST (UTC+2) and set the time to "5" hours on your calendar, this will be UTC "3" hours.
To get the calendar date/time back, you could use components(_:from:) from NSCalendar.
Just check this code:
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"yyyy-MM-dd'T'HH:mm:ssZZZZZ"];
NSDate * dateForNewEvent = [dateFormatter dateFromString: #"2018-07-09T07:24:13+00:00"];
NSLog(#"dateForNewEvent: %#", dateForNewEvent);
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
NSDateComponents *comps = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear|NSCalendarUnitHour|NSCalendarUnitMinute fromDate:dateForNewEvent];
[comps setHour:5];
NSDate *final = [gregorian dateFromComponents:comps];
NSLog(#"final: %#", final);
Output as expected:
2018-07-09 11:11:43.542 jdoodle[22:22] dateForNewEvent: 2018-07-09 07:24:13 +0000
2018-07-09 11:11:43.542 jdoodle[22:22] final: 2018-07-09 05:24:00 +0000

Adding an amount of hours to NSDate isn't working?

I've spent a good few hours trying to make this work. Here's what I'm trying to do:
Take input from a UITextField in the form HH:mm AM/PM
Convert that string into an NSDate object, and update the month/day/year properties of that NSDate to reflect the curren month/day/year.
Add 4 hours to the time of the NSDate object.
That last bit isn't working. It works for times such as 12:00 PM and 12:30 PM but for times such as 2:30 PM, it will output 4:30 PM rather than 6:30 PM as expected. Here is my code, broken up to reflect those three tasks.
Task 1 - checking to see if the text input was HH:mm AM/PM
NSDateFormatter *format = [[NSDateFormatter alloc] init];
[format setLocale:[[NSLocale alloc] initWithLocaleIdentifier:#"en_US"]];
[format setTimeZone:[NSTimeZone systemTimeZone]];
[format setDateFormat:#"HH:mm a"];
NSString *dateString = textField.text;
NSLog(#"input datestring: %#", dateString);
NSDate *parsed = [format dateFromString:dateString];
if (parsed) {
NSLog(#"datestring is valid, %#", parsed);
}
Task 2- Updating the m/d/y components of that date to reflect today's.
//gregorian calendar, get the hour and minute components from the input time
NSCalendar *greg = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
NSDateComponents *components = [greg components: NSCalendarUnitHour | NSCalendarUnitMinute fromDate:parsed];
//get the month/day/year components from the current date
NSDateComponents *comps = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:[NSDate date]];
//set the components of the original date to the month/day/year components of today
[components setYear:comps.year];
[components setDay:comps.day];
[components setMonth:comps.month];
//create the new date.
NSDate* newDate = [greg dateFromComponents:components];
NSLog(#"########### %#", newDate);
Task 3 - Add 4 hours.
int hours = 4 ;
NSString *output;
NSDateComponents *add = [[NSDateComponents alloc] init];
[add setHour:hours];
newDate = [greg dateByAddingComponents:add toDate:newDate options:0];
NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setDateStyle:NSDateFormatterShortStyle];
[df setTimeStyle:NSDateFormatterShortStyle];
output = [df stringFromDate:newDate];
NSLog(#"new date: %#", output);
Log:
2015-08-27 16:03:35.672 Del Taco[1960:117431] input datestring: 2:30 pm
2015-08-27 16:03:35.673 Del Taco[1960:117431] datestring is valid, 2000-01-01 20:30:00 +0000
2015-08-27 16:03:35.673 Del Taco[1960:117431] ########### 2015-08-27 19:30:00 +0000
2015-08-27 16:03:35.674 Del Taco[1960:117431] new date: 8/27/15, 4:30 PM
I think I have this figured out. It was my date formatter where I set the format like this:
#"HH:mm a"
I went to Unicode's website to double check that I was doing this right, and ended up changing my format string to:
#"h:mm a"
And things seem to be working out well!

display last 5days date in ios

I am trying to display last 5 days date. But it display only last date(yesterday). I am using the following code to display it.
.h file:
NSInteger getDist;
NSString *lastdate;
NSDateFormatter *dateFormatter;
NSDate *sevenDaysAgo;
NSDate *dateAfterDecrement;
NSString *dateString;
int i;
viewDidLoad:
NSDate *currDate = [NSDate date];
dateFormatter = [[NSDateFormatter alloc]init];
[dateFormatter setDateFormat:#"dd.MM.YY"];
dateString = [dateFormatter stringFromDate:currDate];
_currentDate.text=dateString;
-(void)display
{
for(i=1;i<=5;i++)
{
lastdate = _currentDate.text;
[dateFormatter setDateFormat:#"dd.MM.YY"];
sevenDaysAgo = [dateFormatter dateFromString:lastdate];
dateAfterDecrement=[sevenDaysAgo initWithTimeIntervalSinceNow:-
(24*60*60)];
}
_currentDate.text = [dateFormatter stringFromDate:dateAfterDecrement];
}
Please suggest me.
Here's how to display today's date, then the last 4 days' dates.
NSDateFormatter* formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"MMM dd, yyyy"];
[formatter setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
int DAY_TO_SECONDS = -60*60*24;
for (int n=0; n<5; n++)
{
NSDate* date = [[NSDate date] dateByAddingTimeInterval:DAY_TO_SECONDS*n];
NSString* dateString = [formatter stringFromDate:date];
NSLog(#"%#", dateString);
}
This produces output like:
2015-02-23 13:18:30.657 ClientInfo[1418:557691] Feb 23, 2015
2015-02-23 13:18:30.658 ClientInfo[1418:557691] Feb 22, 2015
2015-02-23 13:18:30.658 ClientInfo[1418:557691] Feb 21, 2015
2015-02-23 13:18:30.658 ClientInfo[1418:557691] Feb 20, 2015
2015-02-23 13:18:30.658 ClientInfo[1418:557691] Feb 19, 2015
you can decrement current date to this way by the number of days you want to get
NSCalendar *calendar = [NSCalendar autoupdatingCurrentCalendar];
NSDateComponents *datecomponents = [calendar components:NSYearCalendarUnit
| NSMonthCalendarUnit | NSDayCalendarUnit
fromDate:[NSDate date]];
for (int i = 0; i < 5; ++i) {
NSDate *date = [calendar dateFromComponents:datecomponents];
NSLog(#"%#",date);
--datecomponents.day;
}

Next Week Calculation

I have a requirement in which i have to calculate working days i.e from Monday to Friday. if i pass todays date that particular week start date (Monday's Date) and end date(Friday's Date) will be displayed. And i calculated using the below Code.
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:#"yyyy-MM-dd"];// you can use your format.
todayDate= [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc]initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components = [gregorian components:NSWeekdayCalendarUnit | NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit fromDate:todayDate];
int dayofweek = [[[NSCalendar currentCalendar] components:NSWeekdayCalendarUnit fromDate:todayDate] weekday];// this will give you current day of week
[components setDay:([components day] - ((dayofweek) - 2))];// for beginning of the week.
NSDate *beginningOfWeek = [gregorian dateFromComponents:components];
NSDateFormatter *dateFormat_first = [[NSDateFormatter alloc] init];
[dateFormat_first setDateFormat:#"yyyy-MM-dd"];
NSString * dateString2Prev = [dateFormat stringFromDate:beginningOfWeek];
NSDate * weekstartPrev = [dateFormat_first dateFromString:dateString2Prev];
// NSLog(#"The start of the week %#",weekstartPrev);
startDate= [weekstartPrev dateByAddingTimeInterval:60*60*24*1];
//NSLog(#"The date plus one is %#", startDate);
//Week End Date
NSCalendar *gregorianEnd = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *componentsEnd = [gregorianEnd components:NSWeekdayCalendarUnit | NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit fromDate:todayDate];
int Enddayofweek = [[[NSCalendar currentCalendar] components:NSWeekdayCalendarUnit fromDate:todayDate] weekday];// this will give you current day of week
[componentsEnd setDay:([componentsEnd day]+(7-Enddayofweek)+1)];// for end day of the week
NSDate *EndOfWeek = [gregorianEnd dateFromComponents:componentsEnd];
NSDateFormatter *dateFormat_End = [[NSDateFormatter alloc] init];
[dateFormat_End setDateFormat:#"yyyy-MM-dd"];
NSString *dateEndPrev = [dateFormat stringFromDate:EndOfWeek];
NSDate *weekEndPrev = [dateFormat_End dateFromString:dateEndPrev];
endDate= [weekEndPrev dateByAddingTimeInterval: -86400.0];
NSDateFormatter *dateF = [[NSDateFormatter alloc] init];
[dateF setDateFormat:#"dd-MMM-yyyy"];
[dateF setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
[dateF setLocale:[NSLocale localeWithLocaleIdentifier:#"en_GB"]];
endDateString = [dateF stringFromDate:endDate]; //pass this date to time table view controller
NSLog(#"Start date %# and End date %# ",startDate, endDate);
NSDateFormatter *dateF = [[NSDateFormatter alloc] init];
[dateF setDateFormat:#"dd-MMM-yyyy"];
[dateF setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];
[dateF setLocale:[NSLocale localeWithLocaleIdentifier:#"en_GB"]];
startDateString = [dateF stringFromDate:startDate];
NSLog(#"the date start %# ", startDateString);
Now My question is how can I calculate next week for example todays date is Tue 26 Aug 2014. I calculated the current week i.e from Mon 25 Aug 2014 TO Fri 29 Aug 2014 using the above code. how can I calculate next week i.e from 1st September 2014 (monday) To 5th September 2014 (Friday).
i have worked on the similar issues some weeks ago.
I created a category on NSDate. You can use the methods.
- (NSDate *)firstDayOfWeek
{
return [NSDate firstDayOfWeekFor:self];
}
+(NSDate *)firstDayOfWeekFor:(NSDate*)p_Date
{
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *weekdayComponents = [calendar components:NSWeekdayCalendarUnit fromDate:p_Date];
NSDateComponents *componentsToSubtract = [[NSDateComponents alloc] init];
if ([weekdayComponents weekday] == 1)
{
// dimanche, on soustrait 6 jours
[componentsToSubtract setDay:-6];
}
else
{
// autres jours, on soustrait le jour courant et on rajoute 2 (=lundi)
[componentsToSubtract setDay:(-[weekdayComponents weekday] + 2)];
}
return [calendar dateByAddingComponents:componentsToSubtract toDate:[p_Date withoutTime] options:0];
}
- (NSDate *) dateByAddingDays:(NSInteger)p_Days
{
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [[NSDateComponents alloc] init];
[components setDay:p_Days];
return [calendar dateByAddingComponents:components toDate:self options:0];
}

Date selected from UIDatePicker is different from the date being saved

This is how I setup my datePicker
self.datePicker = [[UIDatePicker alloc] init];
self.datePicker.timeZone = [NSTimeZone localTimeZone];
This is how I save the date that I selected
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateStyle:NSDateFormatterMediumStyle];
[formatter setTimeZone:[NSTimeZone localTimeZone]];
dateToSave = [formatter dateFromString:self.dateTextField.text];
NSLog(#"date saved = %#", dateToSave);
If I select Nov 18 2013 from the date picker, the NSLog shows
date saved = 2013-11-17 16:00:00 +0000
However, somewhere in my code, I need to get the difference in days between today's date and the date that I selected in the datepicker.
NSDateComponents *dateComponents = [[NSCalendar currentCalendar] components:NSDayCalendarUnit fromDate:[NSDate date] toDate:dateSaved options:0];
NSLog(#"number of days => %i", [dateComponents day]);
Today is Nov 10. The date I saved is Nov 18. But the number of days difference is 7, instead of 8.
Your time zone is -8. 2013-11-17 16:00:00 +0000 equals to 2013-11-18 00:00:00 -0800.
Use [NSTimeZone timeZoneForSecondsFromGMT:0] instead of [NSTimeZone localTimeZone]
(This answer refers to the updated question about calculating the number of days
between two dates.)
The problem is that [NSDate date] is the current date+time, not the start of the current day. For example, if
[NSDate date] = "2013-11-10 10:00:00"
dateSaved = "2013-11-18 00:00:00" (both in your *local* timezone)
then the difference between
these two dates is "7 days and 14 hours". Therefore you get 7 as the number of days.
So you have to calculate the start of the current day first:
NSDate *startOfDay;
[[NSCalendar currentCalendar] rangeOfUnit:NSDayCalendarUnit
startDate:&startOfDay
interval:NULL
forDate:[NSDate date]];
and then use it in the calculation of the difference:
NSDateComponents *dateComponents = [[NSCalendar currentCalendar] components:NSDayCalendarUnit
fromDate:startOfDay
toDate:dateSaved
options:0];
NSDateFormatter *date_form=[[NSDateFormatter alloc]init];
[date_form setDateFormat:#"dd/MM/yyyy"];
NSDate *seletected_date = [datepicker date];
NSString *dateToSave=[[NSString alloc] initWithFormat:#"%#",[date_form stringFromDate:seletected_date]];
NSLog(#"date saved = %#", dateToSave);
Remove localtimezone

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