How to get UTC date in milliseconds format similiar to new Date().getTime() in javascript?

Question

To solve a time zone issue which is seen when I deploy my project,I need to convert my current date in millisecond format to corresponding UTC date in milliseconds.How can I solve it?

Answer 1

After trying different methods this is what I found to be most efficient and working solution.

       var d = new Date(); //d can be any date we need to convert.
       var millisec= d.getTime()+ (d.getTimezoneOffset() * 60000);

getTimeZoneOffset() returns the offset time in minutes

EDIT:

Actually the above code adds the offset to the local date (instead of subtracting) and my server (which is UTC) allows to get back the local time on the server.

I need the local time in server, as I realised later, we've local times in the API data that we use.

So coming back to the original question, a possible solution to convert local to UTC would be:

       var d = new Date(); //d can be any date we need to convert.
       var millisec= d.getTime() - (d.getTimezoneOffset() * 60000);

In another project later I used the below for date in string form:

a. to convert from local to UTC (while sending to server):

new Date().toUTCString()

b. to convert back to local (while getting data to web from server:

date.toLocaleDateString("en-AU", {
                weekday: 'short', year: 'numeric', month: 'short', day: 'numeric',
                hour12: false, hour: 'numeric', minute: 'numeric', second: 'numeric'
            });