Timestamp with time zone decodes to different locations with different encodings

[bvisness]

I'm not sure this is a bug you can or should do anything about, but I figured you should be made aware of it.

The timestamp with time zone (timestamptz) type decodes with different time.Location values depending on the encoding:

• DecodeText yields a time.Time with location time.UTC
• DecodeBinary yields a time.Time with location time.Local

You can see this for yourself by running the modified tests found in this commit: bvisness@a859409

The reason for this, I think, is that DecodeText uses time.Parse with a format string like "2006-01-02 15:04:05.999999999Z07:00:00". The problem is Z; time.Parse does not recognize Z as a valid timezone specifier and so falls back to parsing as UTC. DecodeBinary simply uses time.Unix, which always produces a local Go time.

As I said, I'm not even really sure if this is a bug since I'm not sure we should depend on a particular time.Location from Postgres, given that the timestamptz from Postgres does not contain any location information. Arguably it could always produce a UTC time, since it's always stored in Postgres as UTC, but as a fully qualified time I'm not sure it even matters.

If anything, the worst part is that there is a discrepancy between the two encodings.

Feel free to close if you don't think it's worth doing anything about!

[jackc]

The problem is Z; time.Parse does not recognize Z as a valid timezone specifier and so falls back to parsing as UTC.

It ends up in UTC, but it does handle the +7 offset.

I agree the situation is not ideal, but I'm not sure what would be an improvement. And then there's the problem of not breaking backwards compatibility.