oc code:
NSDate *date = [NSDate date];
NSTimeZone *zone = [NSTimeZone timeZoneWithName:@"GMT"];
[NSTimeZone setDefaultTimeZone:zone];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter.dateFormat = @"EEE,d MMM yyyy HH:mm:ss 'GMT'";
dateFormatter.locale = [[NSLocal alloc] initWithLocalIdentifier:@"en_US"];
NSString *dateString = [dateFormatter stringFromDate:date];
output:
Wed, 1 Apr 2016 12:51:39 GMT
