NSDate conversion utilities

// Gets UTC NSDate from DateTime(.Net/WCF).

 

+ (NSDate *)fromDateTime:(NSString *)dateTime {

    NSDate *utcDate;

    if ([dateTime isMemberOfClass:[NSNull class]]) {

        utcDate = nil;

    } else {

        NSInteger offset = [[NSTimeZone timeZoneWithName:@"UTC"] secondsFromGMT];

        utcDate = [[NSDate dateWithTimeIntervalSince1970:[[dateTime substringWithRange:NSMakeRange(6, 10)] intValue]] dateByAddingTimeInterval:offset];

    }

    

    return utcDate;

}

 

 

// Converts NSDate to UTC DateTime(.Net/WCF).

- (NSString *)toDateTime {

    NSDateFormatter *utcFormatter = [[NSDateFormatter alloc] init];

    [utcFormatter setTimeZone:[NSTimeZone timeZoneWithName:@"UTC"]];

    

    return [NSString stringWithFormat:@"/Date(%.0f000%@)/", [self timeIntervalSince1970],[utcFormatter stringFromDate:self]];

}

 

// Converts UTC NSDate to local time.

- (NSString *)utcToLocalTime {

    // offset second

    NSInteger seconds = [[NSTimeZone systemTimeZone] secondsFromGMT];

    

    NSDateFormatter *localTimeFormatter = [[NSDateFormatter alloc] init];

    [localTimeFormatter setDateFormat:@"MM/dd/yyyy HH:mm"];

    [localTimeFormatter setTimeZone :[NSTimeZone timeZoneForSecondsFromGMT: seconds]];

    

    return [localTimeFormatter stringFromDate:self];

}