Question

In my sqlite db I have a NSDate field and I create a image file with a unique name using this code and based on that date I load the image.

NSDateFormatter *digitsOnlyDateFormatter = [[NSDateFormatter alloc] init];
[digitsOnlyDateFormatter setDateFormat:@"yyyyMMddHHmmss"];
NSString *imageDateString = [digitsOnlyDateFormatter stringFromDate:[self imageDate]];

If I change the time zone from iphone settings and I add a new record in db, other images saved with another time zone could not be loaded.

I think there is a problem with conversion.
Can someone help me?

Answer 1

Part of NSDateFormatters format can be overridden by user settings: specifically the choice of AM/PM versus 24-hour time.

You can solve this by setting the formatter’s locale. (Note: this is something you should only do in situations like this to create strings that need to be consistent across locales and won’t be displayed to the user).

NSLocale *enUSPOSIXLocale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"];
[digitsOnlyFormatter setLocale:enUSPOSIXLocale];

P.S. if you want the string to be made relative to the same timezone as well, you should also set the formatter’s timezone:

[digitsOnlyFormatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"GMT"]];