This question already has answers here:
Getting date from [NSDate date] off by a few hours
(3 answers)
Closed 8 years ago.
- (void) dateConverter{
NSString *string = [NSString stringWithFormat:#"%# %#", [[self dates]objectAtIndex:0], [times objectAtIndex:0]]; // string = 01-10-2014 11:36 AM;
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"dd-MM-yyyy hh:mm a"];
[dateFormatter setLocale:[NSLocale currentLocale]];
NSDate *date = [[NSDate alloc] init];
date = [dateFormatter dateFromString:string];
NSLog(#"dateFromString = %#", date); // 2014-10-01 18:36:00 +0000
NSTimeInterval timeInterval = [date timeIntervalSince1970];
NSLog(#"dateFromString = %f", timeInterval); // 1412188560.000000
}
I am converting the string to actual date object, but I am getting different behavior
string = 01-10-2014 11:36 AM
is actual value I am trying to convert but getting this
2014-10-01 18:36:00 +0000
what is wrong with it?
The problem is a display issue.
You are using the default date formatter to print the date (NSLog used the description method).
The time is displayed in UTC (GMT) and it looks like you are in timezone -0700. The time is being displayed in timezone offset 0000.
The date/time in the system is based on the GMT time, that way times can be compared across timezones and everywhere on Earth the time is the same in the system at the same time.
Use a date formatter to get the date/time in the format you want.
Example code:
NSString *dateString = #"01-10-2014 11:36 AM";
NSLog(#"dateString = %#", dateString);
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"dd-MM-yyyy hh:mm a"];
[dateFormatter setLocale:[NSLocale currentLocale]];
NSDate *date = [[NSDate alloc] init];
date = [dateFormatter dateFromString:dateString];
NSLog(#"dateFromString = %#", date);
NSString *displayDate = [dateFormatter stringFromDate:date];
NSLog(#"displayDate = %#", displayDate);
Output:
dateString = 01-10-2014 11:36 AM
dateFromString = 2014-10-01 15:36:00 +0000
displayDate = 01-10-2014 11:36 AM
Note: You can supply your own date format to get exactly the format what you want.
Related
This question already has answers here:
NSDate Format outputting wrong date
(5 answers)
Getting date from [NSDate date] off by a few hours
(3 answers)
Closed 9 years ago.
I am trying to convert my date string to NSDate but its return correct date and wrong time.
This is my code :
NSString *dateStr = #"2013-12-20 12:10:40";
// Convert string to date object
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat: #"yyyy-MM-dd HH:mm:ss"];
NSDate *lastUpdatedate = [dateFormatter dateFromString:dateStr];
NSLog(#"lastUpdatedate : %#",lastUpdatedate);
It returns this :
lastUpdatedate : 2013-12-20 06:40:40 +0000
- [NSDate description] (which is called when passing it to NSLog) always prints the date object in GMT timezone, not your local timezone. If you want an accurate string representation of the date, use a date formatter to create a correct string according to your timezone.
As #Leo Natan said, - [NSDate description] always gives date in GMT timezone. If you want to convert into local timezone then use following code.
NSString *dateStr = #"2013-12-20 12:10:40";
// Convert string to date object
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter setDateFormat: #"yyyy-MM-dd HH:mm:ss"];
NSDate *lastUpdatedate = [dateFormatter dateFromString:dateStr];
NSLog(#"lastUpdatedate : %#",[self getLocalTime:lastUpdatedate]);
-(NSDate *) getLocalTime:(NSDate *)date {
NSTimeZone *tz = [NSTimeZone defaultTimeZone];
NSInteger seconds = [tz secondsFromGMTForDate: date];
return [NSDate dateWithTimeInterval: seconds sinceDate: date];
}
OUTPUT:
lastUpdatedate : 2013-12-20 12:10:40 +0000
NSString *dateStr = #"2013-12-20 12:10:40";
NSDateFormatter *dateFormatterTest = [[NSDateFormatter alloc] init];
[dateFormatterTest setDateFormat: #"yyyy-MM-dd HH:mm:ss"];
[dateFormatterTest setLocale:[NSLocale currentLocale]];
NSDate *d = [dateFormatterTest dateFromString:dateStr];
Set NSLocale in your code, and you get perfect result.
You can try this:
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat: #"yyyy-MM-dd HH:mm:ss"];
[dateFormatter setTimeZone:[NSTimeZone systemTimeZone]];
NSDate *lastUpdatedate = [dateFormatter dateFromString:dateStr];
NSTimeInterval sourceGMTOffset = [[NSTimeZone systemTimeZone] secondsFromGMTForDate:lastUpdatedate];
lastUpdatedate = [lastUpdatedate dateByAddingTimeInterval:sourceGMTOffset];
NSLog(#"lastUpdatedate : %#",lastUpdatedate);
I need seven continuous dates' string from a single NSDate. This is what I did,
for (int i = 0; i < 7; i++) {
NSString *dayOfWeek = [self returnStringFromDate:currentDate withStringFOrmat:#"dd - EEEE"];
[daysOfWeekArray addObject:[dayOfWeek uppercaseString]];
currentDate = [currentDate dateByAddingTimeInterval:60 * 60 * 24];
}
- (NSString *)returnStringFromDate:(NSDate *)date
withStringFOrmat:(NSString *)stringFOrmat {
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
NSLocale *locale = [[NSLocale alloc] initWithLocaleIdentifier:#"en_US_POSIX"];
[dateFormatter setLocale:locale];
[dateFormatter setDateFormat:stringFOrmat];
NSString *dateString = [dateFormatter stringFromDate:date];
return dateString;
}
I'm from India, If I have my own time zone(Indian standard time) and passing the currentDate as 01/sun/nov/2015 - it's logging as 2015-10-31 18:30:00 +0000, the above code works correctly. If I change my time zone to US time zone(CST), current date is logging as 2015-11-01 05:00:00 +0000, it's returning one date before for the string. If I try
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:stringFOrmat];
[dateFormatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:#"UTC"]];
NSString *dateString = [dateFormatter stringFromDate:date];
it's working,
but how can I identify which time time zone am I now?
Is it possible to use some common code to find the correct date string from the current time zone of the device?
This question already has an answer here:
NSDateFormatter and Time Zone issue?
(1 answer)
Closed 8 years ago.
-(NSTimeInterval)convertStringToDate:(NSString *) date {
NSString *dateString = date;
NSLog(#"dateString = %#", dateString);
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"dd-MM-yyyy hh:mm a"];
[dateFormatter setLocale:[NSLocale currentLocale]];
NSDate *date1 = [[NSDate alloc] init];
date1 = [dateFormatter dateFromString:dateString];
NSLog(#"dateFromString = %#", date1);
NSString *displayDate = [dateFormatter stringFromDate:date1];
NSLog(#"displayDate = %#", displayDate);
return [date1 timeIntervalSince1970];
}
Why I am getting NSTimeInterval with wrong timezone?
You need to read up on the internal representation of NSDates. An NSDate is saved as the number seconds since midnight on 1 Jan, 1984 GMT (The Mac OS X "epoch date") . It represents an instant in time anywhere on the earth, but using a date in GMT as it's "zero date". To display it, you need to convert it to your local time zone.
NSDate has a couple of methods to convert a date to a number: timeIntervalSince1970, which converts an NSDate to the internet standard, which is the number of seconds since Midnight 1 Jan 1970 (The UNIX "epoch date"), and timeIntervalSinceReferenceDate, which converts to the number seconds since the Mac Epoch date.
If you display a date in NSLog:
NSLog(#"Date = %#", someNSDate);
It will be displayed in GMT.
Honestly, it's unclear what you're asking and my best guess is that you just don't understand the classes at play. I've annotated your code in the hope of aiding your comprehension.
Key point: NSDate does not have a time zone. It's an opaque time stamp.
-(NSTimeInterval)convertStringToDate:(NSString *) date {
// log the input string
NSString *dateString = date;
NSLog(#"dateString = %#", dateString);
// create an object that can apply a locale and a time zone in order to
// convert an NSDate to an NSString and vice versa
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"dd-MM-yyyy hh:mm a"];
[dateFormatter setLocale:[NSLocale currentLocale]];
// get a date that represents exactly now, for no reason as it's about
// to be thrown away
NSDate *date1 = [[NSDate alloc] init];
// convert to the NSDate that represents the given string.
date1 = [dateFormatter dateFromString:dateString];
// log the converted date. BECAUSE NSDATE DOES NOT HAVE A TIME ZONE,
// it will arbitrarily be displayed in UTC. Because it has to be
// displayed in something
NSLog(#"dateFromString = %#", date1);
// convert date1 back into a printable date; this will again apply
// a time zone and locale
NSString *displayDate = [dateFormatter stringFromDate:date1];
NSLog(#"displayDate = %#", displayDate);
// query the date for "The interval between the date object and
// January 1, 1970 at 12:00 a.m. GMT."; return that
return [date1 timeIntervalSince1970];
}
This question already has answers here:
NSDate Format outputting wrong date
(5 answers)
Getting date from [NSDate date] off by a few hours
(3 answers)
Closed 9 years ago.
I am trying to convert my date string to NSDate but its return correct date and wrong time.
This is my code :
NSString *dateStr = #"2013-12-20 12:10:40";
// Convert string to date object
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat: #"yyyy-MM-dd HH:mm:ss"];
NSDate *lastUpdatedate = [dateFormatter dateFromString:dateStr];
NSLog(#"lastUpdatedate : %#",lastUpdatedate);
It returns this :
lastUpdatedate : 2013-12-20 06:40:40 +0000
- [NSDate description] (which is called when passing it to NSLog) always prints the date object in GMT timezone, not your local timezone. If you want an accurate string representation of the date, use a date formatter to create a correct string according to your timezone.
As #Leo Natan said, - [NSDate description] always gives date in GMT timezone. If you want to convert into local timezone then use following code.
NSString *dateStr = #"2013-12-20 12:10:40";
// Convert string to date object
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter setDateFormat: #"yyyy-MM-dd HH:mm:ss"];
NSDate *lastUpdatedate = [dateFormatter dateFromString:dateStr];
NSLog(#"lastUpdatedate : %#",[self getLocalTime:lastUpdatedate]);
-(NSDate *) getLocalTime:(NSDate *)date {
NSTimeZone *tz = [NSTimeZone defaultTimeZone];
NSInteger seconds = [tz secondsFromGMTForDate: date];
return [NSDate dateWithTimeInterval: seconds sinceDate: date];
}
OUTPUT:
lastUpdatedate : 2013-12-20 12:10:40 +0000
NSString *dateStr = #"2013-12-20 12:10:40";
NSDateFormatter *dateFormatterTest = [[NSDateFormatter alloc] init];
[dateFormatterTest setDateFormat: #"yyyy-MM-dd HH:mm:ss"];
[dateFormatterTest setLocale:[NSLocale currentLocale]];
NSDate *d = [dateFormatterTest dateFromString:dateStr];
Set NSLocale in your code, and you get perfect result.
You can try this:
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat: #"yyyy-MM-dd HH:mm:ss"];
[dateFormatter setTimeZone:[NSTimeZone systemTimeZone]];
NSDate *lastUpdatedate = [dateFormatter dateFromString:dateStr];
NSTimeInterval sourceGMTOffset = [[NSTimeZone systemTimeZone] secondsFromGMTForDate:lastUpdatedate];
lastUpdatedate = [lastUpdatedate dateByAddingTimeInterval:sourceGMTOffset];
NSLog(#"lastUpdatedate : %#",lastUpdatedate);
In my project i need to check some format coming from server, So i want to write a regular expression to check the format.
This is the format "03/31/2013 08:00:00" and other format is "03/31/2003 08:00 AM/PM"
How can i check this date formats. Can any one help me.
Regards
Kiran
^(?:\d{2}\/){2}\d{4} \d{2}:\d{2}(?::\d{2}| (?:AM|PM))?$
Note that it won't check for incorrect values.
If you want to get NSDate from this string, you should use NSDateFormetter instead:
NSString * date = #"03/31/2013 08:00:00"; // source string
NSDateFormatter * date_formatter = [[NSDateFormatter alloc] init];
[date_formatter setDateFormat: #"MM/dd/yyyy HH:mm:ss"]; // your date format
NSDate * result = [date_formatter dateFromString: date]; // converting
NSLog (#"%#", [result description]); // log your date result
[date_format release];
Not a real answer to your question about regex but, if you want to get the date from the dateString received from server you can try a trial and error method with the dateFormat of NSDateFormatter.
NSString *dateFormat1 = #"MM/dd/yyyy HH:mm:ss";
NSString *dateFormat2 = #"MM/dd/yyyy hh:mm:ss a";
NSString *dateString = #"03/31/2013 08:00:00 AM";
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
NSLocale *enUSPOSIXLocale = [[NSLocale alloc] initWithLocaleIdentifier:#"en_US_POSIX"];
[dateFormatter setLocale:enUSPOSIXLocale];
[dateFormatter setDateFormat:dateFormat1];
NSDate *date = [dateFormatter dateFromString:dateString];
if (!date) {
[dateFormatter setDateFormat:dateFormat2];
date = [dateFormatter dateFromString:dateString];
}
NSLog(#"Date : %#",date);