Using the moment.js library say i have a datetime with today's date and i would like to replace only the date part of the datetime with another value and keep the time portion the same

I don't want to subtract or add days etc - i have a 3rd party time picker that when you select a time it creates a datetime that is always the current day. I need to send back to server a different datetime - the date is different but keep the time portion from the picker.

example code:

let myDate = "2019-03-15T00:00:00"
let selectedDateTime = "2019-04-04T12:30:00" 

expected result would be:

"2019-03-15T12:30:00"

Thank you

Using the moment.js library say i have a datetime with today's date and i would like to replace only the date part of the datetime with another value and keep the time portion the same

I don't want to subtract or add days etc - i have a 3rd party time picker that when you select a time it creates a datetime that is always the current day. I need to send back to server a different datetime - the date is different but keep the time portion from the picker.

example code:

let myDate = "2019-03-15T00:00:00"
let selectedDateTime = "2019-04-04T12:30:00" 

expected result would be:

"2019-03-15T12:30:00"

Thank you

• javascript
• ecmascript-6
• momentjs

• OK so you want the day of the first date, but the time of the second date? It should be fairly easy with a tool like MomentJS. It has plenty of useful methods to get and set days, hours, minutes and seconds. All you have to do is get the time from the second date, and set it to the first date. – Jeremy Thille Commented Apr 4, 2019 at 15:22

1 Answer 1

The following should solve your problem:

let myDate = moment("2019-03-15T00:00:00")
let selectedDateTime = moment("2019-04-04T12:30:00")

selectedDateTime.date(myDate.date());
selectedDateTime.month(myDate.month());
selectedDateTime.year(myDate.year());

As @JeremyThille suggested, you should take a look at the documentation.