date.getTime

The getTime() method returns the numeric value corresponding to the time for the specified date according to universal time.

getTime() always uses UTC for time representation. For example, a client browser in one timezone, getTime() will be the same as a client browser in any other timezone.

You can use this method to help assign a date and time to another Date object. This method is functionally equivalent to the valueOf() method.

Syntax

dateObj.getTime()

Return value

A number representing the milliseconds elapsed between 1 January 1970 00:00:00 UTC and the given date.

Examples

Using getTime() for copying dates

Constructing a date object with the identical time value.

// Since month is zero based, birthday will be January 10, 1995
var birthday = new Date(1994, 12, 10);
var copy = new Date();
copy.setTime(birthday.getTime());

Measuring execution time

Subtracting two subsequent getTime() calls on newly generated Date objects, give the time span between these two calls. This can be used to calculate the executing time of some operations. See also Date.now() to prevent instantiating unnecessary Date objects.

var end, start;

start = new Date();
for (var i = 0; i < 1000; i++) {
  Math.sqrt(i);
}
end = new Date();

console.log('Operation took ' + (end.getTime() - start.getTime()) + ' msec');

Specifications

Browser compatibility

See also

• Date.prototype.setTime()
• Date.prototype.valueOf()
• Date.now()