Getting date from [NSDate date] off by a few hours

问题

I am using

NSDate *date = [NSDate date];

for getting the date, but the date I get is off by 2 hours.

回答1:

NSDate objects don't have time zones. They represent an absolute moment in time. However, when you ask one for its description (by printing it with NSLog(), e.g.), it has to pick a time zone. The most reasonable "default" choice is GMT. If you're not in GMT yourself, the date will seem to be incorrect, by the amount of your own offset.

You should always use an NSDateFormatter to create a string for display. The formatter's timezone should be set to yours, which is the default.

回答2:

You can get your date corrected like this:

NSDate * dateGMT = [NSDate date];
NSTimeInterval secondsFromGMT = [[NSTimeZone localTimeZone] secondsFromGMT];
NSDate * correctDate = [dateGMT dateByAddingTimeInterval:secondsFromGMT];

回答3:

-(NSDate *)getDateInCurrentSystemTimeZone
{
    NSDate* sourceDate = [NSDate date];
    NSTimeZone* sourceTimeZone = [NSTimeZone timeZoneWithAbbreviation:@"GMT"];
    NSTimeZone* destinationTimeZone = [NSTimeZone systemTimeZone];

    NSInteger sourceGMTOffset = [sourceTimeZone secondsFromGMTForDate:sourceDate];
    NSInteger destinationGMTOffset = [destinationTimeZone secondsFromGMTForDate:sourceDate];
    NSTimeInterval interval = destinationGMTOffset - sourceGMTOffset;

    NSDate* destinationDate = [[NSDate alloc] initWithTimeInterval:interval sinceDate:sourceDate];
    return destinationDate;
}

来源：https://stackoverflow.com/questions/8466744/getting-date-from-nsdate-date-off-by-a-few-hours

标签

objective-c

cocoa

formatting

timezone

nsdate