I know there's a few questions already on this but I keep running into the same error regardless of what I do to my code. I am working in the simulator, I have location set to my long/lat. When I try to convert the current date to zero hours, minutes, seconds I always get this result:
2015-07-10 08:53:19.868 xxxxxxxxxxxxxxxxx[2184:7462272] Today at start of day:2015-07-10 04:00:00 +0000
Here's my code:
NSDate* today = [[NSDate alloc] init];
NSCalendar* currentCalendar = [NSCalendar currentCalendar];
NSDateComponents* dateComponents = [currentCalendar components:NSCalendarUnitMonth | NSCalendarUnitDay | NSCalendarUnitYear fromDate:today];
NSInteger thisMonth = [dateComponents month];
NSInteger thisDay = [dateComponents day];
NSInteger thisYear = [dateComponents year];
NSDateComponents* dayComponents = [[NSDateComponents alloc] init];
[dayComponents setDay:thisDay];
[dayComponents setMonth:thisMonth];
[dayComponents setYear:thisYear];
NSDate* todayAtMidnight = [currentCalendar dateFromComponents:dayComponents];
NSLog(#"Today at start of day:%#", todayAtMidnight);
Even if add
[dayComponents setHour:0]; the hour still comes out as 4.
What am I doing wrong?
To get the beginning of today you can use
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit
fromDate:[NSDate date]];
[calendar setTimeZone:[NSTimeZone timeZoneWithName:#"GMT"]];
NSLog(#"date %#", [calendar dateFromComponents:components]);
Make sure you have the correct timezone
2015-07-10 04:00:00 +0000 is UTC, not your local timezone.
To display it in your local timezone, use an NSDateFormatter:
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter.dateFormat = #"yyyy-MM-dd HH:mm";
[dateFormatter setTimeZone:[NSTimeZone systemTimeZone]];
NSLog([dateFormatter stringFromDate:todayAtMidnight]);
Use NSDateFormatter as follow because system timezone is UTC:
NSDateFormatter * formatter = [[NSDateFormatter alloc] init];
[formatter setTimeZone:[NSTimeZone timeZoneWithName:#"GMT"]];
[formatter setDateFormat:#"yyyy-MM-dd HH:mm:ss"];
NSDate * curDate = [formatter dateFromString:[NSDate date]];
Then you'll get 2015-07-10 00:00:00.
Related
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
This question already has an answer here:
NSDateFormatter - 1 day incorrect?
(1 answer)
Closed 7 years ago.
I try to get first date for the current month from [NSDate new]. My problem is that instead of 2015/06/01 I always receive 2015/05/31. I even try to convert string 20150601 to NSDate and I still receive 2015/05/31.
Here is my CODE (for the second element):
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
[dateFormatter setDateFormat:#"yyyyMMdd"];
[dateFormatter setTimeZone:[NSTimeZone localTimeZone]];
currentMonth = [dateFormatter dateFromString:#"20150601"];
The result is:
(lldb) print currentMonth
(__NSDate *) $0 = 0x79e64820 2015-05-31 21:00:00 UTC
EDIT:
Ok, I understand my mistake - I don't check correctly result of my operations. They always result in UTC.
10x, for answer and all comments. I will be more careful next time.
NSDate *today = [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components = [gregorian components:(NSEraCalendarUnit | NSYearCalendarUnit | NSMonthCalendarUnit) fromDate:today];
components.day = 1;
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
NSTimeZone *zone = [NSTimeZone localTimeZone];
[formatter setTimeZone:zone];
[formatter setDateFormat:#"yyyyMMdd"];
NSDate *dayOneInCurrentMonth = [gregorian dateFromComponents:components];
NSString *currentMonth = [formatter stringFromDate:dayOneInCurrentMonth];
NSLog(#"%#",currentMonth);
Output
2015-06-08 14:07:30.924 NSDATEDemo[1943:39838] 20150601
Create NSDateComponents from [NSDate date], set the current day to 1 and re-create your NSDate object:
- (NSDate *) dateAtStartOfMonth
{
//Not tested!!!
NSDateComponents *comp = [[NSCalendar currentCalendar] components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit) fromDate:[NSDate date]];
[comp setDay:1];
return [[NSCalendar currentCalendar] dateFromComponents:comp];
}
i want to get the current date in format like this 24 February 2014 . i want
also get Islamic date in the same format as 5 jumada al-awwal 1436
how can i do that i saw other thing but most care about integer components.
i wrote this code which just get components
NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:[NSDate date]];
NSInteger day = [components day];
NSInteger month = [components month];
NSInteger year = [components year];
NSLog(#"%#",components);
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"EEEE"];
NSLog(#"%#", [dateFormatter stringFromDate:[NSDate date]]);
i used this to Islamic date
NSCalendar *islamicCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSIslamicCalendar];
NSDate *today = [NSDate date];
[islamicCalendar rangeOfUnit:NSDayCalendarUnit startDate:&today interval:NULL forDate:today];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setCalendar:islamicCalendar];
[dateFormatter setTimeStyle:NSDateFormatterFullStyle];
[dateFormatter setDateStyle:NSDateFormatterFullStyle];
//english output
dateFormatter.locale = [[NSLocale alloc] initWithLocaleIdentifier:#"en_US_POSIX"];
NSString * islamicDateString = [dateFormatter stringFromDate:today];
NSLog(#"%#", islamicDateString);
Hi I have a countdown timer in my app and I am looking for a way to take my timestamp date and modify it based on the time zone without formatting it. The time stamp is GMT and it looks like this:
theDate = [NSDate dateWithTimeIntervalSince1970:1387929601];
Then I have my countdown formatter here:
-(void)updateCountdownText
{
//Update the Countdown Label
NSCalendar *calendar = [[NSCalendar alloc]initWithCalendarIdentifier:NSGregorianCalendar];
int units = NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
NSDateComponents *components = [calendar components:units fromDate:[NSDate date] toDate:theDate options:0];
[dateLabel setText:[NSString stringWithFormat:#"%d%c %d%c %d%c %d%c", [components day], 'd', [components hour], 'h', [components minute], 'm', [components second], 's']];
}
Since I'm already formatting the timestamp below all i would like to do is take the GMT timestamp number and convert it according to the local time zone. So I would just like to add the time zone code before the dateWithTimeInterval and then change that number (keeping it a timestamp) according to the time zone. Is this possible? Thanks!
Try this one:
//Timestamp convert to NSDate
double time=[myString doubleValue];//in yourcase mystring=#"1387929601"; mystring is timestamp
NSTimeInterval interval =time ;
NSDate *online = [NSDate dateWithTimeIntervalSince1970:interval];
NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
[dateFormatter setDateFormat:#"hh:mm a dd-MMM-yyyy"];
NSLog(#"Timestamp date is: %#", [dateFormatter stringFromDate:online]);
NSString *mystr=[dateFormatter stringFromDate:online];
NSCalendar *cal = [NSCalendar currentCalendar];
NSDate *now = [dateFormatter dateFromString:mystr];
value1=([[NSTimeZone localTimeZone] secondsFromGMT]);
value1=value1/3600;
float value123=((value1) * 3600);
NSTimeZone *tz = [NSTimeZone timeZoneForSecondsFromGMT:(value123)]; // for PST
NSDateComponents *dc = [cal components: NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit fromDate:now];
[cal setTimeZone:tz];
NSDate *newDate = [cal dateFromComponents:dc];
NSDateFormatter *dateFormatter1 = [[[NSDateFormatter alloc] init] autorelease];
[dateFormatter1 setDateFormat:#"hh:mm a dd-MMM-yyyy"];
NSLog(#"result: %#", [dateFormatter1 stringFromDate:newDate]);
May it will work for you.
happy coding...
Use NSDateFormatter to get correct time zone of your theDate object.
NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
[formatter setTimeZone:[NSTimeZone localTimeZone];
NSTimeZone has a property secondsFromGMT. So you can use [NSTimeZone systemTimeZone].secondsFromGMT; to obtain the difference, add it to your time interval and instantiate the date.
Format the NSDate to adjust for time zone:
NSTimeZone *tz = [[NSTimeZone timeZoneForSecondsFromGMT:(-8 * 3600)];
[dateFormatter setTimeZone:tz];
NSString* s = [dateFormatter stringFromDate:now];
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.