Output only. The time at which the document was created.
This value increases monotonically when a document is deleted then recreated. It can also be compared to values from other documents and the readTime of a query.
A timestamp in RFC3339 UTC "Zulu" format, with nanosecond resolution and up to nine fractional digits. Examples: "2014-10-02T15:01:23Z" and "2014-10-02T15:01:23.045123456Z".
Output only. The time at which the document was last changed.
This value is initially set to the createTime then increases monotonically with each change to the document. It can also be compared to values from other documents and the readTime of a query.
A timestamp in RFC3339 UTC "Zulu" format, with nanosecond resolution and up to nine fractional digits. Examples: "2014-10-02T15:01:23Z" and "2014-10-02T15:01:23.045123456Z".