Datetime type storing empty string for "0001-01-01T00:00:00Z"

[pawan (Pawan Rawal)]

@ahsan

In this particular line in dgraph

@ahsan

Now after this PR, when we are not accepting empty datetime in mutation, I think it would be right to return “0001-01-01T00:00:00Z” (a zero time) instead of an empty string.

Yeah, we should be returning the zero time(“0001-01-01T00:00:00Z”) instead of an empty string if the user stored that in the DB. Also look into the linked issue while you fix this to avoid introducing a regression.