Metadata datetime handling.

Relates to https://code.usgs.gov/ghsc/geomag/geomag-plots/-/issues/338

Currently, (at least some) metadata for readings in the metadata service include times without a timezone. In algorithms, using obspy UTCDateTime, these times are interpreted as UTC. In javascript, these times are interpreted as local time.

• Check pydantic formatting for UTCDateTime, it should use UTC and the "Z" timezone abbreviation for unambiguous interpretation everywhere.
• Need to coordinate with geomag-plots/operations app to ensure this does not break current implementation.

@jmfee These docs would indicate that output metadata will have truncated times (no Z) unless we specify different behavior: https://pydantic-docs.helpmanual.io/usage/exporting_models/#json_encoders

We could use something like this:

class Config:
       json_encoders = {
           UTCDateTime: lambda utc: utc.strftime("%Y-%m-%dT%H:%M:%S.%fZ"),
       }

but this would only apply to the starttime/endtime of the metadata, not the embedded metadata(readings, etc.). Furthermore, these lines would need to exist in the base models for all metadata types. If we don't want to go this route, I think we could use something similar for the metadata(Dict) that will format times as the output we want. Thoughts?

I think the second option might be the way to go since we aren't delivering these base classes (readings, etc.) directly over the webservice

@pcain : this is the function currently being used and it could be updated: https://code.usgs.gov/ghsc/geomag/geomag-algorithms/-/blob/master/geomagio/pydantic_utcdatetime.py#L44

@jmfee This line has been updated in !122 (merged)

mentioned in merge request !122 (merged)

added In Review label

added Bug label

marked the checklist item Check pydantic formatting for UTCDateTime, it should use UTC and the "Z" timezone abbreviation for unambiguous interpretation everywhere. as completed

mentioned in commit 190eb8fb

closed with merge request !122 (merged)

removed In Review label