According to the micropython documentation, the parameters to setting the clock should be
(year, month,day, hour,minute, second, millisecond, tzinfo)
but if I feed them in that order, the date isn't set right.
I am using an Atom Matrix.
Here is an example of one way that fails, and one that works
machine.RTC().datetime((2020,12,1,10,20,30,0,0))
(2020, 12, 1, 20, 30, 0, 1, 336)
machine.RTC().datetime()
(2020, 12, 1, 1, 20, 30, 17, 239019)
machine.RTC().datetime((2020,12,1,0,10,20,30,0))
(2020, 12, 1, 10, 20, 30, 1, 336)
machine.RTC().datetime()
(2020, 12, 1, 1, 10, 20, 32, 759064)
The first example is how the docs say.
The second example puts a zero in front of the hour, and removes one from the end (to keep it to 8 parameters)