Objective-C setting NSDate to current UTC

Question

Is there an easy way to init an NSDate with the current UTC date/time?

Answer 1

[NSDate date];

You may want to create a category that does something like this:

-(NSString *)getUTCFormateDate:(NSDate *)localDate
{
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:@"UTC"];
    [dateFormatter setTimeZone:timeZone];
    [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSString *dateString = [dateFormatter stringFromDate:localDate];
    [dateFormatter release];
    return dateString;
}

Answer 2

NSDate is a reference to an interval from an absolute reference date, January 1, 2001 00:00 GMT. So the class method [NSDate date] will return a representation of that interval. To present that data in a textual format in UTC, just use the NSDateFormatter with the appropriate NSTimeZone (UTC) to render as needed.

Answer 3

NSDate objects encapsulate a single point in time, independent of any particular calendrical system or time zone. Date objects are immutable, representing an invariant time interval relative to an absolute reference date (00:00:00 UTC on 1 January 2001).

Swift version:

extension NSDate {
    func getUTCFormateDate() -> String {
        let dateFormatter = NSDateFormatter()
        let timeZone = NSTimeZone(name: "UTC")
        dateFormatter.timeZone = timeZone
        dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
        return dateFormatter.stringFromDate(self)
    }
}