Date to Millisecond Calculators

Several date to millisecond calculators, useful when coding countdown timers, cookie expiration settings or other date related scripts. The calculators are coded in JavaScript.

If you need to do date math across timezones, follow this link to a couple date/timezone tools at the bottom of this page.

The known data:

Your computer's time:

equals
milliseconds
since
-- the start of Unix Epoch Time
in your time zone ( ).

Convert a millisecond value to a date string

this (milli )second time number:

is the equivalent of this date string in time zone

Date to milliseconds converter

a date string
examples:
"Mon Jun 18 2007 00:00:00 GMT-0400"
or "09/23/2000"
or "09/23/2000 9:45:00"



What date would that be?

Your computer's time:


equals this date:

A temporal value converted to milliseconds


equals so many (milli )seconds:

Milliseconds converted to a temporal value

So many (milli )seconds:

equals so many :

How much time between now and then?

Your computer's time:

and this date:
examples:
"Mon Jun 18 2007 00:00:00 GMT-0400"
or "09/23/2000"
or "09/23/2000 9:45:00"


are so many apart:

How much time between now and then (using a millisecond date value)?

Your computer's time:

and this date in (milli )seconds:

are so many apart:

Date and Time Math Across Timezones

Date and Time Plus/Minus Quantity of Time

This date and time
in timezone
so many
equals this date and time in this timezone

Date/Time Subtraction

This date and time
in timezone
minus
this date and time
in timezone
equals so many :

78 Comments

  1. Good, but not satisfying all the needs. Is there an other tool like this which can be used for all the types in calendar and gregorian calendar or date.

  2. Let my input date is “01/01/2009” in MM/DD/YYYY format. How I will calculate in java script that the input date is not before “09/30/2009” and not after “03/31/2011”. Please sent me the Java script code to my E-Mail. Thanks

  3. This is a great website you have and I believe my site can be a great benfit to yours. As its related to the same industry sector, your viewers might appreciate our link to your page. ACalculator.com

  4. Milliseconds to date string different than date to milliseconds for the same date:

    1392126870991 results in Tue Feb 11 2014 14:54:30 GMT+0100 (W. Europe Standard Time), while

    Tue Feb 11 2014 14:54:30 GMT+0100 (W. Europe Standard Time) gives 1392126870000.

    Is there a way to ensure that Tue Feb 11 2014 14:54:30 GMT+0100 (W. Europe Standard Time) gives also 1392126870991?

    Thanks in advance.

    1. Thanks for pointing this out. I guess there may be a bug in my code that converts Tue Feb 11 2014 14:54:30 GMT+0100 to milliseconds. might not respect the timezone portion.
      -Colin

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