time.monotonic() returns no fraction of seconds after *long* runtime.

[ThomasAtBBTF]

CircuitPython version

Adafruit CircuitPython 5.4.0  LoC BeR M4 base board with samd51g19

Code/REPL

import time
time.monotonic()
# in code and the command line, the fraction of seconds was always .0

Behavior

I did observe this behavior last night on a device that was running for many days.
Note: that also after breaking the code with ctrl-c and importing time
and entering time.monotonic() in the command line, the fraction of seconds was always .0
Only after microcontroller.reset() this behavior stopped.

I will try to reproduce this with other controllers and CP 7.0.
But it will take days until I have a result ....

Description

No response

Additional information

No response

[dhalbert]

This is a known problem with time.monotonic(), because of the low precision of floats (5-6 digits). We recommend you use time.monotonic_ns(), if you board supports it (must have longints). Or, if it works for you, you can use supervisor.ticks_ms(), which wrap but keep their precision.

See #342 (comment) for some background on the precision issue.

[ThomasAtBBTF]

Ok, thank you taking a look at this so quickly and for the explanation.
It would be helpful if is this information would be available at:
https://circuitpython.readthedocs.io/en/latest/shared-bindings/time/

Also a possibility to programmatically reset to time.monotonic "0" would be helpful, as this situation can be detected quite easily, now that I know how,