Class ServerValue (2.9.1)

ServerValue(value)

A value that is calculated by the server.

Values: SERVER_VALUE_UNSPECIFIED (0): Unspecified. This value must not be used. REQUEST_TIME (1): The time at which the server processed the request, with millisecond precision. If used on multiple fields (same or different documents) in a transaction, all the fields will get the same server timestamp.