Context

Vuetify uses Math.floor for most of the calculations, so it is not symmetrical either.

Other adapters:

• moment: symmetrical
• date-fns: symmetrical
• luxon: correct for hours, but non-symmetrical for weeks

Problem

• when calculating diffs by weeks
  • the result is not symmetrical because of Math.floor
• when calculating diffs by hours, minutes and seconds
  • the result is not symmetrical because of Math.round
  • it returns -0 instead of 0 (JS quirk we should rather hide)

Suggestion

• always return based on largestUnit

It would align with current implementation in Vuetify (for positive range) while fixing the values in negative range gaining the symmetry.