Weird date result adding 1 month to a given date - ios

I am using following piece of code to get next week date from a given date at 12:00am:
NSDate *now = [NSDate date];
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit |NSHourCalendarUnit fromDate:now];
[components setHour:0];
NSDate *todayDate = [calendar dateFromComponents:components];
int daysToAdd = 7;
NSDate *tomorrowDate = [todayDate dateByAddingTimeInterval:60*60*24*daysToAdd];
NSString *stringDate = [NSString stringWithFormat:#"%#",tomorrowDate];
todoItemDueDateText.text = stringDate;
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
[dateFormatter setDateFormat:#"EEEE, dd MMMM YYYY"];
NSString *fechasimulada = [dateFormatter stringFromDate:tomorrowDate];
dateFieldSimulatedText.text = fechasimulada;
If I log the result date, it is working fine.
Now, a similar piece of code to get next month date from a given date at 12:00am:
NSDate *now = [NSDate date];
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit fromDate:now];
[components setHour:0];
NSDate *todayDate = [calendar dateFromComponents:components];
//NSDate *today = [NSDate date];
NSDateComponents* dateComponents = [[NSDateComponents alloc]init];
[dateComponents setMonth:1];
//NSCalendar* calendar = [NSCalendar currentCalendar];
NSDate* tomorrowDate = [calendar dateByAddingComponents:dateComponents toDate:todayDate options:0];
NSString *stringDate = [NSString stringWithFormat:#"%#",tomorrowDate];
todoItemDueDateText.text = stringDate;
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
[dateFormatter setDateFormat:#"EEEE, dd MMMM YYYY"];
NSString *fechasimulada = [dateFormatter stringFromDate:tomorrowDate];
I don't know why, but the second piece of code gives the expected date but -1 hour.
UPDATE:
I will show you the dates:
Source date (today at 12:00am)+7 h
Next week date from previous given date:
Next month date from previous given date:

NSDate takes Daylight Savings into account. If you cross a DST day, you'll experience this issue.

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

selecting only working days from NSDate in objective c

My concern is..if am having text field with start date.when i am selecting date from calendar with day of Friday..then i want to skip weekend days saturday and sunday in enddate text field...i tried like this
NSString *strCurrentDate;
NSString *strNewDate;
NSDate *date = [NSDate date];
NSDateFormatter *df =[[NSDateFormatter alloc] init];
[df setDateFormat:#"yyyy-MM-dd"];
[df setTimeStyle:NSDateFormatterMediumStyle];
strCurrentDate = [df stringFromDate:date];
NSLog(#"Current Date and Time: %#",strCurrentDate);
int hoursToAdd = roundedUp;
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components = [[NSDateComponents alloc] init];
[components setDay:hoursToAdd];
NSDate *newDate= [calendar dateByAddingComponents:components toDate:date options:0];
[df setDateFormat:#"yyyy-MM-dd"];
[df setTimeStyle:NSDateFormatterMediumStyle];
strNewDate = [df stringFromDate:newDate];
NSLog(#"New Date and Time: %#",strNewDate);
while ([strNewDate compare:strCurrentDate] == NSOrderedAscending)
{
NSDateComponents *dateComponents = [calendar components:NSWeekdayCalendarUnit fromDate:strNewDate];
if (dateComponents.weekday == friday)
{
count = count+2;
NSLog(#"count = %d", count);
NSDateComponents *oneDay = [[NSDateComponents alloc] init];
[oneDay setDay:2];
NSString *endDate = [strNewDate dateByAddingTimeInterval:2*60*60*24];
// [oneDay setDay:2];
}
}
But I am not getting only week days… so can any one do the needful… thank u in advance :)
To get the next working day from now use the method isDateInWeekend of NSCalendar
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
// Strip the time portion of the date
NSDate *date = [calendar startOfDayForDate:[NSDate date]];
do {
// add 1 day until the result is not in a weekend
date = [calendar dateByAddingUnit:NSCalendarUnitDay value:1 toDate:date options:NSCalendarMatchNextTime];
} while (![calendar isDateInWeekend:date]);
NSLog(#"Next Workday: %#", date);

Unable to store proper date in NSDate

I am trying to store dates in NSDate but not getting proper output.
Writing the code snippet below.
NSDate *firstDate = [NSDate dateWithYear:2015 month:12 day:1 ];
Expecting the output to be 2015-12-1 18:30:00 +0000.
But getting 2015-11-30 18:30:00 +0000
Ignore the time stamp.
dateWithYear:month:day is a category method which is there in the 3rd party calendar which I am using.the code of the method is as follows:
+ (NSDate *)dateWithYear:(NSInteger)year month:(NSInteger)month day:(NSInteger)day {
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
NSDateComponents *components = [NSDate componentsWithYear:year month:month day:day];
return [calendar dateFromComponents:components];
}
return [calendar dateFromComponents:components];
is
+ (NSDateComponents *)componentsWithYear:(NSInteger)year month:(NSInteger)month day:(NSInteger)day {
NSDateComponents *components = [[NSDateComponents alloc] init];
[components setYear:year];
[components setMonth:month];
[components setDay:day];
return components;
}
Thanks in Advance.
There are many ways to set a date from data,
NSDateFormatter :
NSString *dateString = #"2015-12-01";
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter.dateFormat = #"yyyy-MM-dd";
NSDate *date1 = [dateFormatter dateFromString:dateString];
NSDateComponents : (you can add setSecond, setMinute, setHour for a specific time)
NSDateComponents *dateComps = [[NSDateComponents alloc] init];
[dateComps setYear:2015];
[dateComps setMonth:12];
[dateComps setDay:1];
NSDate *date2 = [[NSCalendar currentCalendar] dateFromComponents:dateComps];

Comparing 2 dates, error in NSDateComponents

I have 2 dates. Date1 in yyyy-MM-dd 21:00:00 +0000. Date2 in yyyy-MM-dd
I need to compare it and get age result.
Problem is that Ia have an error in NSDateComponents string.
NSDate *date1 = [NSDate date];
NSDate *date2temp = uBirthdate;
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"yyyy-MM-dd"];
NSString *dateString = [dateFormatter stringFromDate:date2temp];
[dateString stringByAppendingString:#" 21:00:00 +0000"];
NSDate *date2 = [dateFormatter dateFromString:dateString];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:NSYearCalendarUnit fromDate:date2 toDate:date1 options:0];
NSInteger editedAge = components.year;
NSLog(#"%d ", editedAge);
It will be better to cut off '21:00:00 +0000' from date1, but I do not know how can I do it

Constructing an NSDate from today's date and a string with the time

If I have a string representing a time, say "10:45 am", and do the following to parse the string:
NSDateFormatter *dateFormat;
dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:#"h:mm a"];
NSLog(#"%#", [dateFormat dateFromString:#"10:45 AM"]);
I would get this logged:
2013-09-09 17:52:30.416 TimeTest[49491:a0b] 2000-01-01 15:45:00 +0000
How can I create an NSDate for the current day at the given time? I tried this
NSDate *date = [NSDate date];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"h:mm a"];
NSDate *time = [formatter dateFromString:#"10:45 AM"];
NSDateComponents *timeComponents = [[NSCalendar currentCalendar] components:(NSHourCalendarUnit | NSMinuteCalendarUnit ) fromDate:time];
NSDateComponents *dateComponents = [[NSCalendar currentCalendar] components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit) fromDate:date];
NSDateComponents *newComponents = [[NSDateComponents alloc]init];
newComponents.timeZone = [NSTimeZone systemTimeZone];
[newComponents setDay:[dateComponents year]];
[newComponents setMonth:[dateComponents month]];
[newComponents setYear:[dateComponents year]];
[newComponents setHour:[timeComponents hour]];
[newComponents setMinute:[timeComponents minute]];
NSCalendar *gregorianCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDate *combinedDate = [gregorianCalendar dateFromComponents:newComponents];
NSLog(#"%#", combinedDate);
with the result
2013-09-09 19:57:14.506 TimeTest[49712:a0b] 2019-03-06 15:45:00 +0000
How should I go about this?
I'm not exactly sure what you are looking for. For what I understand, you want to build a date with the current year, month and day, but with your supplied time by parsing it from a string.
If that is the case, as others have pointed out, you need to play with NSDateComponents.
Based on your code I wrote these lines. They should build a date by merging two dates. The current one and the one you parsed.
// Get the full current date
NSDate *date = [NSDate date];
// Get the current calendar
NSCalendar *calendar = [NSCalendar currentCalendar];
// Split the date into components but only take the year, month and day and leave the rest behind
NSDateComponents *dateComponents = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit) fromDate:date];
// Build the date formatter
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"h:mm a"];
// Convert the string time into an NSDate
NSDate *time = [formatter dateFromString:#"10:45 AM"];
// Split this one in components as well but take the time part this time
NSDateComponents *timeComponents = [[NSCalendar currentCalendar] components:(NSHourCalendarUnit | NSMinuteCalendarUnit ) fromDate:time];
// Do some merging between the two date components
dateComponents.hour = timeComponents.hour;
dateComponents.minute = timeComponents.minute;
// Extract the NSDate object again
NSDate *result = [calendar dateFromComponents:dateComponents];
// Check if this was what you where looking for
NSLog(#"%#",result);
Please be aware that this sample code is by far non-optimized. There are more crisp ways to obtain what you are looking for by using time intervals, but I felt like you wanted a dirty simple example on how to do components copy and paste and then extracting dates.
This will create a date for the beginning of the day in the current time zone.
NSDate *today = [NSDate date];
NSTimeInterval interval;
NSCalendar *cal = [NSCalendar currentCalendar];
[cal rangeOfUnit:NSDayCalendarUnit
startDate:&today
interval:&interval
forDate:today];
Now we add the time:
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
// I have to set the locale to posix_en_us, as my system is using 24hour style as default
dateFormatter.locale = [[NSLocale alloc] initWithLocaleIdentifier:#"en_US_POSIX"];
[dateFormatter setDateFormat:#"hh:mm a"];
NSDate *time = [dateFormatter dateFromString:#"10:45 AM"];
NSDateComponents *comps = [cal components:(NSHourCalendarUnit | NSMinuteCalendarUnit)
fromDate:time];
NSDate *dateAndTime = [cal dateByAddingComponents:comps
toDate:today
options:0];
dateAndTime will now be todays date with 10:45 am in the local timezone.
controlling in the debugger:
po dateAndTime
$0 = 0x41b7df138c00000d 2013-09-10 08:45:00 +0000
This is correct, as my timezone is 2 hours ahead to GMT, as we still have summer time.

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