Return UTC differential value from adafruit_pyportal.get_local_time()

[CedarGroveStudios]

It would be very useful for calculating time-dependent values (such as sunrise and sunset times) if the adafruit_pyportal.get_local_time module also returned the UTC differential value for the local time zone.

[ladyada]

that data is requested
https://github.com/adafruit/Adafruit_CircuitPython_PyPortal/blob/master/adafruit_pyportal.py#L86
but we don't do anything with it
https://github.com/adafruit/Adafruit_CircuitPython_PyPortal/blob/master/adafruit_pyportal.py#L555
i dont think the python time module can track UTC - so would that be some other time struct? like where would we keep track of it :)

[CedarGroveStudios]

I believe that in Python3, the base time is UTC and localtime is derived from that. Does CircuitPython do it that way or is the foundational time the local time? If that's the case, then perhaps the offset could be derived from a json query and stored as an attribute in pyportal.py. (I'm way out of my league here.)

[ladyada]

hmm - how would you ask Cpython for utc and local time?

[makermelissa]

Couldn't you just temporarily set your timezone to something like "Etc/UTC" to get UTC?

[CedarGroveStudios]

Here's how it works in the Python3 REPL:

Jupyter QtConsole 4.3.1
Python 3.6.3 (v3.6.3:2c5fed8, Oct  3 2017, 17:26:49) [MSC v.1900 32 bit (Intel)]
Type 'copyright', 'credits' or 'license' for more information
IPython 6.2.1 -- An enhanced Interactive Python. Type '?' for help.

>>> import time

>>> time.localtime()
Out[2]: time.struct_time(tm_year=2019, tm_mon=3, tm_mday=18, tm_hour=0, tm_min=3, tm_sec=26, tm_wday=0, tm_yday=77, tm_isdst=1)

>>> time.gmtime()
Out[3]: time.struct_time(tm_year=2019, tm_mon=3, tm_mday=18, tm_hour=7, tm_min=3, tm_sec=32, tm_wday=0, tm_yday=77, tm_isdst=0)

>>> time.gmtime()[3] - time.localtime()[3]
Out[4]: 7

[CedarGroveStudios]

^^ I'll try that for now. Thanks @makermelissa!

[ladyada]

sounds like we should add gmtime() to time at some point, wanna open up an issue on circuitpython for that? then we would be able to have two times!

[CedarGroveStudios]

I'll do that! I'll close this issue since I think we have a potential workaround with @makermelissa 's suggestion.

[ladyada]

yay!

[CedarGroveStudios]

Done! adafruit/circuitpython #1663