so in my app I want to subtract two dates. The first date is set date and the second one is the current date. So i tried this code:
NSString *setDateString = [NSString stringWithFormat:#"12:30"];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
NSDate *setDate = [dateFormatter dateFromString:setDateString];
NSTimeInterval interval = [[NSDate date] timeIntervalSinceDate:setDate];
But it counts the interval from 1970. But I need from the current day. Can anyone help?
I assume you want the difference between now and 1230 hrs of today. This can be done by
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components =[gregorian components:(NSDayCalendarUnit|NSYearCalendarUnit|NSMonthCalendarUnit) fromDate:today];
[components setHour:12];
[components setMinute:30];
[components setSecond:0];
NSDate *setDate=[gregorian dateFromComponents:components];
NSTimeInterval interval = [[NSDate date] timeIntervalSinceDate:setDate];
[gregorian release];
The reason it doesn't work for you is you've not given the format correctly. Alternatively, you can describe it correctly in setDateString by specifying all the components rather than just hour and minute.
Related
I am trying to fetch images from photo library within the range of two dates and I am getting the images successfully. Using PHAsset Library
Now the problem is that am not able to get images between two times of the same day like between 12:10PM to 12:30PM
Using below code
NSDate *startDate = [self getDateForDay:30 andMonth:9 andYear:2016 andHour:12 andMinute:10 andSecond:0];
NSDate *endDate = [self getDateForDay:30 andMonth:9 andYear:2016 andHour:12 andMinute:30 andSecond:0];
--
-(NSDate*) getDateForDay:(NSInteger) day andMonth:(NSInteger) month andYear:(NSInteger) year andHour:(NSInteger) hour andMinute:(NSInteger) minute andSecond:(NSInteger) second{
NSDateComponents *comps = [[NSDateComponents alloc] init];
[comps setDay:day];
[comps setMonth:month];
[comps setYear:year];
[comps setHour:hour];
[comps setMinute:minute];
[comps setSecond:second];
NSCalendar* gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
[gregorian setTimeZone:[NSTimeZone timeZoneWithAbbreviation:#"GMT"]];
NSDate *date = [gregorian dateFromComponents:comps];
return date;
}
-- And passing those dates to below method to get images
PHFetchResult *result = [self getAssetsFromLibraryWithStartDate:startDate andEndDate:endDate];
Dates and time coming correct when i print in log but not getting images
How to solve this problem ?
The date created here would be in UTC timezone and yours may vary. Which is why the predicate may not return you correct results.
Make sure you have set the timezone of calendar to your system timezone before creating a date from it like:
NSCalendar* gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
[gregorian setTimeZone: [NSTimeZone systemTimeZone]];
NSDate *date = [gregorian dateFromComponents:comps];
That will create the date in your local timezone and generate correct results.
I created an NSDate by dateFromComponents, using NSCalendar with NSGregorianCalendar identifier, here's the strange part:
The date get incorrect if it's before a certain point in time before 1900/12/31
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
NSDateComponents *components = [[NSDateComponents alloc] init];
components.year = 1900; components.month = 12; components.day = 31;
NSDate *date = [calendar dateFromComponents:components];
components.year = 1901; components.month = 1; components.day = 1;
NSDate *date2 = [calendar dateFromComponents:components];
NSLog(#"%#",calendar.timeZone.description);
NSLog(#"%#",date);
NSLog(#"%#",date2);
The log will be:
2016-05-25 14:58:21.014 date[79754:2192157] Asia/Shanghai (GMT+8) offset 28800
2016-05-25 14:58:21.015 date[79754:2192157] 1900-12-30 15:54:17 +0000
2016-05-25 14:58:21.015 date[79754:2192157] 1900-12-31 16:00:00 +0000
As you can see, there is a 5 minutes gap during the day.
However, if I set the timeZone by [NSTimeZone timeZoneForSecondsFromGMT:], even with the same seconds deviation - 28800, it will be normal.
What is the cause of this?
No, the date isn't incorrect. Instead, the NSCalendar code knows things about calendars that you wouldn't dream about, like calendars changing their time offsets at some points in time in the past.
You asked for the Asia/Shanghai calendar to convert two dates, one on the day before they changed their time zone, one on the day after they changed their time zone, and both times are converted correctly. That night everyone in Shanghai had to adjust their watches.
Interesting question. What you are seeing is the effects of a time zone change from Local Mean Time to China Standard Time on 01-01-1901 when the clocks were turned back 05m43s.
More details here.
Try this!!
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [[NSDateComponents alloc] init];
[components setYear:1987];
[components setMonth:3];
[components setDay:17];
[components setHour:14];
[components setMinute:20];
[components setSecond:0];
NSDate *date = [calendar dateFromComponents:components];
Hope this Help:)
I am trying to get the days of a week in reference to their date.
Ex.: 14th October is a Wednesday.
I am creating a collection view cell and displaying the date as follows.
In the 14th cell it would display Wednesday, but how to get the next day as Thursday, then Friday...and so on.
I have got todays date and which day it is as follows,
day = [components day];
week = [components month];
year = [components year];
weekday = [components weekday];
NSString *string = [NSString stringWithFormat:#"%ld.%ld.%ld", (long)day, (long)week, (long)year];
NSLog(#"%#",string);
NSDate *todayDate = [NSDate date]; // get today date
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"EEEE"];
NSString *convertedDateString = [dateFormatter stringFromDate:todayDate];// here convert date in
NSLog(#"Today formatted date is %#",convertedDateString);
And i have found this method online, which returns the days in string when you pass the integer, but i am having trouble in this too, not understanding which integer to pass every time so I get different strings.
static inline NSString *stringFromWeekday(int weekday){
static NSString *strings[] = {
#"Sunday",
#"Monday",
#"Tuesday",
#"Wednesday",
#"Thursday",
#"Friday",
#"Saturday",
};
return strings[weekday];
}
You already got everything in place. You should be getting the correct day name in the convertedDateString string. You just have to add 24 hours to your todayDate object and use the dateformatter again to get the next day.
NSDate *todayDate = [NSDate date]; // get today date
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"EEEE"];
NSString *convertedDateString = [dateFormatter stringFromDate:todayDate];// here convert date in
You can get the next day like this.
NSDateComponents *dateComponents = [[NSCalendar currentCalendar] components:(NSDayCalendarUnit | NSMonthCalenderUnit | NSYearCalenderUnit | NSWeekdayCalendarUnit) fromDate:today];
[dateComponents setDay:dateComponents.day+1];
NSDate *nextDay = [dateComponents date];
// Get the day by following same approach in the top
You will get days in a week from today using below code.
NSDate *today = [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc]
initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *weekdayComponents =
[gregorian components:(NSDayCalendarUnit | NSWeekdayCalendarUnit) fromDate:today];
NSInteger day = [weekdayComponents day];
NSInteger weekday = [weekdayComponents weekday];
i have one date like '2014-11-16T15:42:14' in server and now i want to convert this date into such formate like '1 day and 2 hours ago'.
can any body help me how can i solve this?
I wholeheartedly accept your down votes.(Please explain me the reason for you down vote such that i will not repeat my mistake).
Look at that example that will help you definately.
Copied From Here
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDate *date = [NSDate date];
NSDateComponents *components = [[NSDateComponents alloc] init];
[components setWeekOfYear:1];
[components setHour:12];
NSLog(#"1 week and twelve hours from now: %#", [calendar dateByAddingComponents:components toDate:date options:0]);
iOS Programming: I just want to let iOS7 get the "America/Chicago" current date and time.
I searched a lot on Internet, but there are a lot of different solutions. I tried several solutions, but they do not work.
You can use the NSCalendar and NSTimezone classes. The following code segment demonstrates retrieving the current hour and minute. Extending it to retrieve other date components is straight-forward -
long hour;
long minute;
NSCalendar *cal=[NSCalendar currentCalendar];
NSDate *now=[NSDate date];
NSTimeZone *tz=[NSTimeZone timeZoneWithName:#"America/Chicago"];
[cal setTimeZone:tz];
NSDateComponents *comp=[cal components:NSHourCalendarUnit|NSMinuteCalendarUnit fromDate:now];
hour=[comp hour];
min=[comp minute];
You can use this method,
- (NSDate *) getCountryDateWithTimeZone:(NSString *)zone
{
NSDate *now = [NSDate date];
NSTimeZone *szone = [NSTimeZone timeZoneWithName:zone];
NSInteger sourceGMTOffset = [szone secondsFromGMTForDate:now];
NSTimeInterval interval = sourceGMTOffset;
NSDate *destinationDate = [NSDate dateWithTimeInterval:interval sinceDate:now];
return destinationDate;
}
And,
[self getCountryDateWithTimeZone:#"America/Chicago"];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"yyyy-MM-dd HH:mm:ss"];
NSString *firstDate = #"2014-06-05 12:55:00";
NSDate *date=[dateFormatter dateFromString:firstDate];
NSDate *currentDate = [NSDate date];
NSDateComponents *components = [[NSCalendar currentCalendar] components:NSDayCalendarUnit|NSHourCalendarUnit|NSMinuteCalendarUnit|NSSecondCalendarUnit fromDate:date toDate:currentDate options:0];
NSLog(#"The difference between from date and to date is %d days and %d hours and %d minute and %d second",components.day,components.hour,components.minute,components.second);
Output:
DateBookApp[1179:70b] The difference between from date and to date is 0 days and 22 hours and 57 minute and 12 Second