Allow user to work in timezones besides UTC

[thodson-usgs]

All data is converted to UTC; however, some users might prefer to work in a local timezone.

[jjkennedy]

Is it possible to only pull the date column from groundwater levels? I'm finding that some sites do not have a time associated with the measurement and it's throwing an error because it can't convert that to a datetime index.

[elbeejay]

To update the status of this issue:

• Some documentation on converting timezones out of UTC is provided in Error when merging across timezones #62 based on a suggestion in Better documentation of time zones and time zone awareness of objects would be helpful #61
• Handling of "incomplete" date-time information, such as measurements without times, was handled in add ability to coerce incomplete datetime info + tests #58

At this time there is still no built-in functionality for getting queries back in whatever timezone you want, they do come back with UTC-localized timestamps.

[mishranurag]

I assume that the daily data is in local time zone. However, the label on the time has Z on it which can be confusing.

[thodson-usgs]

That's a bug alright.
The REST API can accept time zones, so perhaps we could handle this better.
https://waterservices.usgs.gov/rest/IV-Service.html
Unsure what users will want as the default behavior in this case. I vote for UTC as default, otherwise there could be unexpected consequences. Having no default would leave the data in multiple time zones, which isn't ideal. Neither can we assume a default time zone based on the compute clock, because the user may be in a different time zone from their compute.

[wzell-usgs]

On the subject of UTC - Is it expected behavior that the returned datetime index is UTC +0 rather than local UTC? E.g., for a randomly selected GW site with IV service, here is the dataRetrieval result (UTC+0):

and here is the NWIS web interface 'view data' (UTC-6):

I think can programmatically convert to local UTC using the tz_cd with the site information but perhaps it is preferred to have dataRetrieval handle that conversion?

[thodson-usgs]

Correct, we decided to stick with USGS, unlike the web interface. The reason being what is "local time" when you're working analyzing data from multiple timezones?