Round Conversion Into Lower Precision Durations?

[PTaylor-us]

Currently, converting from 1_999.milliseconds() to Seconds yields 1.seconds(). I feel like it makes a lot of sense to round these values, but the current behavior may actually be the expectation of the user given that arithmetic operations don't round either.

[devjgm]

I'd avoid round, but truc, floor, and ceil are predictable and do seem useful.