How can I convert timestamp to date and convert date to timestamp after editing provided by firebase? [duplicate]

Question

I am working with cloud functions. Actually, I am a flutter amateur, but cloud functions require JavaScript, so I don't have any Idea. I am getting a timestamp from this code.

admin.firestore.Timestamp.now()    

But I want to edit the timestamp and upload it to another collection. I want to convert the current month to the next month. i.e. - February to March and upload to another document.

Thanks a lot in Advance!