new Date(..).getTime() is not equal to moment(..).valueOf() in momentJS?

Question

new Date(..).getTime() should return a timestamp in milliseconds. According to the documentation of momentJS the expression moment(..).valueOf() should do the same (return timestamp in milliseconds for a given date).

I checked with the following example data:

var timeStampDate = new Date("2015-03-25").getTime(); //timestamp in milliseconds? > 1427241600000 var timeStampMoment = moment("03-25-2015", "MMDDYYYY").valueOf(); //timestamp in milliseconds? > 1427238000000 

As you can see the results were not the same.

Now I'm searching for a function in momentJS that returns to me the exact same data that the expression new Date(..).getTime().

Answer 1

Date constructor doc:

The UTC time zone is used to interpret arguments in ISO 8601 format that do not contain time zone information

moment constructor doc:

Unless you specify a timezone offset, parsing a string will create a date in the current timezone

so specifying the timezone in the moment constructor results in the same behavior as Date:

var timeStampMoment = moment("03-25-2015 +0000", "MM-DD-YYYY Z").valueOf(); //> 1427241600000 

Answer 2

When you pass in the same value to Date and moment (at least in Chrome a few years on), you get the same value from both values.

new Date("2015-03-25").getTime() 1427241600000 moment("03-25-2015", "MMDDYYYY").valueOf() 1427259600000 new Date("03-25-2015").getTime() 1427259600000 

What you actually hit was just a different guess of the Date format in Date.parse