Add optional timezone offset for NTP.set_time()

[theelectricmayhem]

Updated NTP.set_time() to accept an optional tz_offset which adjusts the recorded time by that number of hours.

[brentru]

@theelectricmayhem Thanks for the PR, looks great!

I can't merge this in because it is failing on Black's code formatting check (https://github.com/adafruit/Adafruit_CircuitPython_NTP/pull/10/checks?check_run_id=661578319#step:11:8).

Please follow this guide to install and run Black on your code: https://learn.adafruit.com/improve-your-code-with-pylint/black

[theelectricmayhem]

Thanks! Hopefully Black cleaned up that formatting issue. Is there a particular target version of python used for Adafruit libraries I should be using with Black?

[brentru]

Seems like 3.5? Via the Action:

Run black --check --target-version=py35 .

[theelectricmayhem]

Seems like 3.5? Via the Action:

Run black --check --target-version=py35 .

Sweet. Thanks

[jepler]

Not all time zone offsets are whole hours. Please consider following the example of Python, which uses seconds for timezone offsets (time.timezone). It would also be good if the docstring states what the units of tz_offset are, and whether to expect the number to be positive or negative depending where you are, e.g., if you follow how Python defines timezone:

The offset of the local timezone, in seconds west of UTC (negative in most of Western Europe, positive in the US, zero in the UK).

[theelectricmayhem]

That's absolutely the right way to do it. Thanks! New PR

[jepler]

Aha I didn't see that the PR had already been merged. Looking forward to the next one and thanks @theelectricmayhem !