Ion-datetime with timestamp firestore (Ionic 4)

Hello guys,

I have an event object with two fields: StartDate and EndDate.
I want to store them as timestamp in the firestore and edit in page it with [(ngModel)] = “event.StartDate”.

How to work with ion-datetime in timestamp format?

I already tried to use the moment, I tried to use Date.
When saved saves as string. And when I edit not bind in ion-datetime.

Can someone help me with someone example?