i don't think this can be solved in a way that is independent of the
chosen unit, as it requires a concept of "whole time-units" (as in
"whole numbers"); whether these be seconds or minutes would be
completely arbitrary.

(`5 minutes % 3 = 0 minutes` would be true if based on seconds because
`5 minutes = 3 * 100 seconds + 0 minutes` but `5 minutes % 3 = 2
minutes` based on minutes because `5 minutes = 3 * 1 minute + 2 minutes`.)