The Gaussian-School of Higher-Arithmetic (1831, updated 2022); tutorial #21 page 12c.

The Arithmetic of Clocks, page 12c.

It is of course possible to express the arithmetic of clocks in flat numbers but it is a bit pointless. Note that if on the flat rotational plane we make repeated complete rotations of the plane, as we see with for example the Earth returning to her same sidereal alignment every 23 hours, 56 minutes, and 4 seconds, we are failing to take account of the changing calendar. In other words, a neo-Pythagorean with his "flat-earth-arithmetic" might think that one day is the same as the next, but in reality of course, that is utter nonsense.