Get current date in milliseconds

Solution 1:

There are several ways of doing this, although my personal favorite is:

CFAbsoluteTime timeInSeconds = CFAbsoluteTimeGetCurrent();

You can read more about this method here. You can also create a NSDate object and get time by calling timeIntervalSince1970 which returns the seconds since 1/1/1970:

NSTimeInterval timeInSeconds = [[NSDate date] timeIntervalSince1970];

And in Swift:

let timeInSeconds: TimeInterval = Date().timeIntervalSince1970

Solution 2:

Casting the NSTimeInterval directly to a long overflowed for me, so instead I had to cast to a long long.

long long milliseconds = (long long)([[NSDate date] timeIntervalSince1970] * 1000.0);

The result is a 13 digit timestamp as in Unix.

Solution 3:

NSTimeInterval milisecondedDate = ([[NSDate date] timeIntervalSince1970] * 1000);

Solution 4:

You can just do this:

long currentTime = (long)(NSTimeInterval)([[NSDate date] timeIntervalSince1970]);

this will return a value en milliseconds, so if you multiply the resulting value by 1000 (as suggested my Eimantas) you'll overflow the long type and it'll result in a negative value.

For example, if I run that code right now, it'll result in

currentTime = 1357234941

and

currentTime /seconds / minutes / hours / days = years
1357234941 / 60 / 60 / 24 / 365 = 43.037637652207

Solution 5:

extension NSDate {

    func toMillis() -> NSNumber {
        return NSNumber(longLong:Int64(timeIntervalSince1970 * 1000))
    }

    static func fromMillis(millis: NSNumber?) -> NSDate? {
        return millis.map() { number in NSDate(timeIntervalSince1970: Double(number) / 1000)}
    }

    static func currentTimeInMillis() -> NSNumber {
        return NSDate().toMillis()
    }
}