Improved sleep_for, allows alarms up to 28 days long

[ahnlak]

Leaning heavily (read: copying) on similar work done for Inky Frames, expanded sleep_for() function to allow for sleeps longer than 24 hours - by adding the day component to the alarm, this maximum can be stretched to a month (capped at 28 days)

[Gadgetoid]

Thank you. I don't know why it didn't occur to me to switch into epoch time and back to handle rollover. Wood for the trees I suppose.

[ahnlak]

Ahh, the advantage of decades of C programming where you don't have any meaningful date routines so you just automatically reduce all dates/times to a long int and do maths 🤣