Firebase - what data type is firebase.database.ServerValue.TIMESTAMP

Question

I was looking around to find the data type of a TIMESTAMP. I looked in the docs but it doesn't mention anything about type.

Are these a Float or a Double or another type?

const currentDate = Date.now();
const timeStamp = firebase.database.ServerValue.TIMESTAMP;

This is the way firebase.database.ServerValue.TIMESTAMP appears inside the RTDB:

The `firebase.database.ServerValue.TIMESTAMP` is for the Firebase Realtime Database, but you tagged with `google-cloud-firestore`. Both have a server-side timestamp sentinel, but it'd be good to know which one you're actually asking about. — Frank van Puffelen, Nov 07 '20 at 21:15
I'm more interested in `Date.now()` for the `RTDB`. I thought that they would be the same datatype — Lance Samaria, Nov 07 '20 at 21:17

Frank van Puffelen · Accepted Answer · 2020-11-07T21:22:42.380

0

The ServerValue.TIMESTAMP field is a so-called sentinel value. Upon writing it to the database, it is actually a map: { ".sv": "timestamp" }. But then in the database itself, and when you read a field of this value back, you'll get a regular number (the milliseconds since the epoch).

Depending on your platform, this asymmetrical type can lead to interesting programming challenges. For example, see: When making a POJO in Firebase, can you use ServerValue.TIMESTAMP?

edited Nov 07 '20 at 21:22

answered Nov 07 '20 at 21:20

Frank van Puffelen

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when you say a regular number, is the regular number a float or a double? Or is a number in javascript the same as a NSNumber in Obj-c? – Lance Samaria Nov 07 '20 at 21:21
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When reading a value back, it's a long number: the number of milliseconds since the epoch. – Frank van Puffelen Nov 07 '20 at 21:23

Firebase - what data type is firebase.database.ServerValue.TIMESTAMP

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