Datetime formatting/math? | adafruit | Page 1

bright epoch Dec 24, 2024, 9:12 AM

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What I'd like is to be able to take a timestamp in UTC, and have it format a string (or at least return components) in a given time zone, automatically applying DST adjustments.

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Datetime formatting/math?

honest spade Dec 24, 2024, 2:22 PM

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adafruit_datetime, https://docs.circuitpython.org/projects/datetime/en/latest/api.html is a subset of what regular Python's datetime class provides.
https://github.com/micropython/micropython-lib/blob/master/python-stdlib/datetime/datetime.py is a micropython library that does have date/time arithmetic and less support for formatting.

bright epoch Dec 24, 2024, 11:46 PM

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When I try to use the format specifier {0:%d}, as shown here, I get an error that it's invalid

honest spade Dec 25, 2024, 12:38 AM

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That example is just ... wrong. I'm tracking down what was meant.

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Also I see in the code that there is datetime arithmetic, but it was not included in the documentation!

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Use this documentation: https://docs.circuitpython.org/projects/datetime/en/latest/index.html. The link you gave above is outdated or something. I'm not sure why it's in readthedocs.

honest spade Dec 25, 2024, 1:05 AM

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ok, I tracked this down. Somebody else created some readthedocs projects for a few circuitpython libraries almost four years ago. They are based on very old versions of the libraries. I've asked them to delete those projects.

bright epoch Dec 25, 2024, 1:45 AM

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Where does datetime get the current time? (I'm on an ESP32-S3, with a ds3231 attached)

bright epoch Dec 25, 2024, 2:49 AM

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I can see in the CP sources that RTC.datetime ends up calling gettimeofday, but I can't find a definition for that anywhere in the CP sources (using github's search feature).

honest spade Dec 25, 2024, 1:39 PM

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It's calling getttimeofday() as provided by a few board's SDK, e.g., the Espressif ESP-iDF. In the below, cxd56 is Sony Spresense.

ports/espressif/common-hal/rtc/RTC.c:16:    gettimeofday(&tv_now, NULL);
ports/cxd56/common-hal/pulseio/PulseIn.c:36:    gettimeofday(&tv, NULL);
ports/cxd56/common-hal/rtc/RTC.c:17:    gettimeofday(&tv, NULL);

#Datetime formatting/math?