iPhone NSDateFormatter Timezone Conversion

问题:

I am trying to create a formatter that will convert the date format shown to an NSDate object:

NSString *dateStr = @"2010-06-21T19:00:00-05:00";
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"yyyy-MM-dd'T'HH:mm:ssZZZ"];
NSDate *date = [dateFormat dateFromString:dateStr];  

The issue is the timezone -05:00, which is not parsed properly with the format above. Any suggestions?

回答1:

Honestly, you'll just have to change the source data (removing the colon) before running it through the formatter. Your original date string is non-standard and none of the time zone format strings will work properly on it.

You can see the valid inputs on unicode.org.

ZZZ e.g. "-0500"

ZZZZ e.g. "GMT-05:00"

Nothing for "-05:00"

回答2:

To process the time zone with the colon in it, you just need to use 5 'Z's. This is a pretty common date format, the ISO-8601 format. This will only work on iOS 6.x+

-(NSDate *) dateFromString:(NSString *)string {

    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ssZZZZZ"];

    return [formatter dateFromString:string];
}

回答3:

May be I missed something but ZZ worked for me. I used:

@"yyyy-MM-dd'T'HH:mm:ss.SSSZZ"

for

2014-02-27T08:00:00.000+04:00

回答4:

This is the default time format I got from a Sinatra ActiveRecord backend. Here is my solution.

-(NSDate *) dateFromString:(NSString *)string{
    NSMutableString * correctedDateString = [[NSMutableString alloc] initWithString:string];
    [correctedDateString deleteCharactersInRange: NSMakeRange(22, 1)];

    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ssZZZ"];

    return [formatter dateFromString:correctedDateString];
}

回答5:

This is the only solution that worked for me:

[dateFormat setDateFormat:@"yyyy-MM-dd'T'HH:mm:ssZZZZZ"];

回答6:

5 ZZZZZ - heres a category I wrote with some sample of GMT to BST

https://github.com/clearbrian/NSDateFormatter_ISO_8601