I would like to convert a Unix timestamp e.g 1315401371 stored as a NSString into a date format of 23:00 12 October 2011.
There are a number of similar questions being ask in relation to this however I wish to use billymeltdown / nsdate-helper methods
I have imported the 2 files (.h and .m) into my project, but have not manage to get further than that.
There is documentation, which I have read, however I am still very new to objective C and do not understand how I actual use the libraries.
Thanks in Advance.
You should use NSDateFormatter
NSTimeInterval timestamp = 1315401371;
NSDate *date = [NSDate dateWithTimeIntervalSince1970:timestamp];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"HH:mm dd MMMM yyyy"]; // use one d for 7 October instead of 07 October
// For english month names
NSLocale *usLocale = [[NSLocale alloc] initWithLocaleIdentifier:#"en_US"];
[dateFormatter setLocale:usLocale];
[usLocale release];
NSString *dateString = [dateFormatter stringFromDate:date];
[dateFormatter release];
Related
I have a timestamp coming from server that looks like this:
2013-04-18T08:49:58.157+0000
I've tried removing the colons, I've tried all of these:
Converting an ISO 8601 timestamp into an NSDate: How does one deal with the UTC time offset?
Why NSDateFormatter can not parse date from ISO 8601 format
Here is where I am at:
+ (NSDate *)dateUsingStringFromAPI:(NSString *)dateString {
NSDateFormatter *dateFormatter;
dateFormatter = [[NSDateFormatter alloc] init];
//#"yyyy-MM-dd'T'HH:mm:ss'Z'" - doesn't work
//#"yyyy-MM-dd'T'HH:mm:ssZZZ" - doesn't work
//#"yyyy-MM-dd'T'HH:mm:sss" - doesn't work
[dateFormatter setDateFormat:#"yyyy-MM-dd'T'HH:mm:ss'Z'"];
[dateFormatter setTimeZone:[NSTimeZone timeZoneWithName:#"GMT"]];
// NSDateFormatter does not like ISO 8601 so strip the milliseconds and timezone
dateString = [dateString substringWithRange:NSMakeRange(0, [dateString length]-5)];
return [dateFormatter dateFromString:dateString];
}
One of my biggest questions is, is the date format I have above really ISO 8601? All the examples I have seen from people the formats of each are slightly different. Some have ...157-0000, others don't have anything at the end.
This works for me:
NSString *dateString = #"2013-04-18T08:49:58.157+0000";
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"yyyy-MM-dd'T'HH:mm:ss.SSSZ"];
// Always use this locale when parsing fixed format date strings
NSLocale *posix = [[NSLocale alloc] initWithLocaleIdentifier:#"en_US_POSIX"];
[formatter setLocale:posix];
NSDate *date = [formatter dateFromString:dateString];
NSLog(#"date = %#", date);
There is New API from Apple! NSISO8601DateFormatter
NSString *dateSTR = #"2005-06-27T21:00:00Z";
NSISO8601DateFormatter *formatter = [[NSISO8601DateFormatter alloc] init];
NSDate *date = [formatter dateFromString:dateSTR];
NSLog(#"%#", date);
I also have the native API, which is way cleaner... This is the implementation I got in my DateTimeManager class:
+ (NSDate *)getDateFromISO8601:(NSString *)strDate{
NSISO8601DateFormatter *formatter = [[NSISO8601DateFormatter alloc] init];
NSDate *date = [formatter dateFromString: strDate];
return date;
}
Just copy and paste the method, it would do the trick. Enjoy it!
The perfect and best solution that worked for me is:
let isoFormatter = ISO8601DateFormatter();
isoFormatter.formatOptions = [ISO8601DateFormatter.Options.withColonSeparatorInTime,
ISO8601DateFormatter.Options.withFractionalSeconds,
ISO8601DateFormatter.Options.withFullDate,
ISO8601DateFormatter.Options.withFullTime,
ISO8601DateFormatter.Options.withTimeZone]
let date = isoFormatter.date(from: dateStr);
For further more detail, you can refer to apple's official documentation: https://developer.apple.com/documentation/foundation/nsiso8601dateformatter
I have a string "2012-06-04" and am having a hard time converting it to: June 4, 2012.
Is there a quick way to transform this? I come from a ruby world where you would convert everything to seconds and that back out to the format you need it. Is there a reference that shows how to do that?
Thanks
One way to do so is to convert the string to an NSDate using the NSDateFormatter with the 2012-06-04 format, and then convert the NSDate back to a string using the June 4, 2012 format:
NSString* input = #"2012-06-04";
NSDateFormatter* df = [[NSDateFormatter alloc] init];
[df setDateFormat:#"yyyy-MM-dd"];
NSDate* date = [df dateFromString:input];
[df setDateFormat:#"MMMM d, yyyy"];
return [df stringFromDate:date];
The format string's syntax is described in UTS #35.
Something like
NSDateFormatter *fromDateFormatter = [[NSDateFormatter alloc] init];
fromDateFormatter.dateFormat = #"yyyy-MM-dd";
NSDate *date = [fromDateFormatter dateFromString:#"2012-06-04"];
NSLog(#"%#", date);
NSDateFormatter *toDateFormatter = [[NSDateFormatter alloc] init];
toDateFormatter.dateFormat = #"MMMM d, yyyy";
NSString *toDate = [toDateFormatter stringFromDate:date];
NSLog(#"%#", toDate);
#=> 2012-05-30 20:51:12.205 Untitled[1029:707] 2012-06-03 23:00:00 +0000
#=> 2012-05-30 20:51:12.206 Untitled[1029:707] June 4, 2012
To work this out you can use Apple's class references NSDateFormatter and other sources like this IPHONE NSDATEFORMATTER DATE FORMATTING TABLE and some trial and error
I am loading in dates from my web service, I'm sending dates in the format (GMT times): 02/11/11 10:56:09
I am creating an NSDate form this using NSDateFormatter as such:
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"dd/MM/yyyy HH:mm:ss"];
NSDate *journeyDate = [dateFormatter dateFromString:str];
[dateFormatter release];
This works great, after I'm comparing this to the current date to get relative time intervals.
The problem is when the phone is set up in a different timezone, when I load in the date from my api, and use the date formatter, what seems to be happening is the phone is assuming the date string is local time and it's converting it to GMT.
Example:
I load in a date with the time 10am from the api.
The phone is set to PDT.
The date formatter is creating an NSDate assuming that my date string with 10am, is actually relevant to the phone.
I end up with a date and time equal to 5pm, adding 10 hours.
I am trying to specify in my date formatter that the string is GMT, but I'm having trouble, I've tried the following, adding GMT to the format:
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"dd/MM/yyyy HH:mm:ss GMT"];
NSDate *journeyDate = [dateFormatter dateFromString:str];
[dateFormatter release];
This is not working.
Can anyone give any advice ?
Solution
Just a recap, I got it working with a terrible work around by appending GMT to the original string, and formatting that:
NSString * cheat = [NSString stringWithFormat:#"%# GMT", str];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"dd/MM/yyyy HH:mm:ss zzzz"];
NSDate *journeyDate = [dateFormatter dateFromString:cheat];
[dateFormatter release];
return journeyDate;
This was a kind of unstable hack, because if the string changed to include a timezone, it wouldn't work anymore. For anyone who needs to do as myself, the following is just a quick example on how to create an NSTimeZone.
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"dd/MM/yyyy HH:mm:ss"];
[dateFormatter setTimeZone:[NSTimeZone timeZoneWithName:#"UTC"]];
NSDate *journeyDate = [dateFormatter dateFromString:str];
[dateFormatter release];
return journeyDate;
Thanks for the quick help.
I suspect you just want to use NSDateFormatter.setTimeZone to force it to use UTC. You don't want to change the format string because presumably the string doesn't include the letters "GMT" - instead, you want to change which time zone the string is interpreted in, which is what setTimeZone will do.
You should use the setTimeZone method: http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSDateFormatter_Class/Reference/Reference.html
i'm wondering why my setDateFormat does not work when i use it with a different timezone , here GMT :
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:#"GMT"]];
[dateFormatter setDateFormat:#"dd-MM-YYYY"]; //this doesn't work, nothing appears
//[dateFormatter setDateStyle:NSDateFormatterMediumStyle]; //this works
but if i use the default timeZone, it works :
NSDateFormatter *Dateformat = [[NSDateFormatter alloc]init];
[Dateformat setDateFormat:#"dd-MM-YYYY HH:mm:ss"]; //this works
Thanks for your help
Paul
Have you tried to NSLog a string by using this dateFormatter, its woking for me..when i make a string as-
NSString *dateStr = [dateFormatter stringFromDate:[NSDate date]];
NSLog(#"%#",dateStr);
and its give me this -
09-08-2011
Additionaly, you should probably be using: [dateFormatter setDateFormat:#"dd-MM-yyyy"] instead of [dateFormatter setDateFormat:#"dd-MM-YYYY"].
Using YYYY is a common mistake according to the apple documentation. It returns the year number of the year the week is in (according to ISO week numbering scheme). This can be off one year. Lowercase yyyy is normally the correct version.
See: iphone Get current year as string
(The comment of Anna Karenina)
I want to ask 2 questions about the NSDate of iPhone application.
1) How to set the
NSDate *startDay to 01-01-2010 and NSDate *endDay to 31-12-2010
2) how many day between the startDay and the endDay.
What should I do? Thank you very much.
For handling dates with different formats you would need to use NSDateFormatter
NSDateFormatter *format = [[NSDateFormatter alloc] init];
[format setDateFormat:#"mm-dd-yyyy"];
To get date with specified format
NSString *dateString = [format stringFromDate:date];
To create a date from string with specified format:
NSDate *date = [format dateFromString:dateString];
NSDateFormatter documentation
To find the difference between two dates:
NSTimeInterval interval = [endDay timeIntervalSinceDate:startDay];
timeIntervalSinceDate documentation