C# version of Javascript Date.getTime()

Question

What is the best way in c# to get the same result of javascript date.gettime() call?

The getTime() method returns the number of milliseconds since midnigh

Answer 1

The Java and JavaScript Date.getTime() methods return the number of milliseconds since 1 Jan 1970 00:00:00 GMT.

Since .NET represents dates in Ticks (1 Tick = 0.1 nanoseconds or 0.0001 milliseconds) since 1 Jan 0001 00:00:00 GMT, we must use a conversion formula where 621355968000000000 is the offset between the base dates in Ticks and 10000 the number of Ticks per Millisecond.

Ticks = (MilliSeconds * 10000) + 621355968000000000
MilliSeconds = (Ticks - 621355968000000000) / 10000

Answer 2

I guess this will do the trick :)

public double MilliTimeStamp(DateTime TheDate)
        {
            DateTime d1 = new DateTime(1970, 1, 1);
            DateTime d2 = TheDate.ToUniversalTime();
            TimeSpan ts = new TimeSpan(d2.Ticks - d1.Ticks);

            return ts.TotalMilliseconds;
        }

Answer 3

(DateTime.Now - new DateTime (1970, 1, 1)).TotalMilliseconds

Answer 4

Since JavaScript time is with respect to UTC, I think you will need something like this:

var st = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
var t  = (DateTime.Now.ToUniversalTime() - st);
// t.TotalMilliseconds

Now you can use the TotalMilliseconds property of the Timespan.

Answer 5

Here is an extension method based off Enigma State's answer

public static Int64 GetJavascriptTimeStamp(this DateTime dt)
{
    var nineteenseventy = new DateTime(1970, 1, 1);
    var timeElapsed = (dt.ToUniversalTime() - nineteenseventy);
    return (Int64)(timeElapsed.TotalMilliseconds + 0.5);
}

To use it for the current time:

var timeStamp = DateTime.Now.GetJavascriptTimeStamp();

Answer 6

The correct implementation (assuming the current time) is as follows:

DateTime utcNow = DateTime.UtcNow;
DateTime epoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
long ts = (long)((utcNow - epoch).TotalMilliseconds);