Calculating Time for clock's preset

[skimask]

I thought about calculating time in seconds from midnight, but represanting 24 Hours in seconds require more than 16Bit.

Then don't use every second...use every 2 seconds. 60*60*24=86,400 / 2 = 43,200.
Or you could use every 1.5 seconds, 60*60*24=86,400 / 1.5 = 57.600.

Or use 'binary time'...if there is such a thing...
Instead of dividing a day into 86,400 chunks, it's broken up into 65,536 chunks, each chunk being 1.318359375 seconds long.