NSDate to GMTDate to JSON format

3
votes

I want to convert my Local date ([NSDate date]) to GMT to create a JSON string (/Date(1324435876019-0000)/).

My code works fine when i set my clock to EST time zone when i change my timezone to PST my code still acts as EST. Can you please tell me what is the problem is following code?

        NSDate *localDate = [NSDate date];
    NSTimeInterval timeZoneOffset = [[NSTimeZone systemTimeZone] secondsFromGMT]; // You could also use the systemTimeZone method
    NSTimeInterval gmtTimeInterval = [localDate timeIntervalSinceReferenceDate] - timeZoneOffset;
    NSDate *gmtDate = [NSDate dateWithTimeIntervalSinceReferenceDate:gmtTimeInterval];
    NSString *time = [NSString stringWithFormat:@"/Date(%@-0000)/", [NSNumber numberWithLongLong:[gmtDate timeIntervalSince1970] * 1000]];
2
objective-ciosnsdatenstimeintervalnstimezone
Current time is 2011-12-20 05:15:00 +0000 But if i NSLog gmtDate i am getting out put as 1) ESt tim zone: 2011-12-21 03:15:00 +0000 2) PSTtime zone :2011-12-21 06:15:00 +0000. Which is wrong. I think i am not getting right GMT date. What you think ? – AAV

2 Answers

7
votes

You can get the epoch GMT time by simply calling timeIntervalSince1970.

NSString *time = [NSString stringWithFormat:@"/Date(%lld-0000)/", 
                     (long long)([[NSDate date] timeIntervalSince1970] * 1000)];
0
votes

@joe and @tommy you are right. Even i implemneted the same way as you mentioned. Problem was in server database. I found a hack. I just need to add 18000 (5 hr) second to the current local date and i am good. So code is 

        NSDate *localDate = [NSDate date];
    NSTimeInterval gmtTimeInterval = [localDate timeIntervalSinceReferenceDate] + 18000;
    NSDate *gmtDate = [NSDate dateWithTimeIntervalSinceReferenceDate:gmtTimeInterval];

    NSString *time = [NSString stringWithFormat:@"/Date(%@-0000)/", [NSNumber numberWithLongLong:[gmtDate timeIntervalSince1970] * 1000]];