Calendar Nerdery repost
We should make Dec 31 New Year‘s Day so the quarters could all be more equal lengths:
Dec 31 to Mar 31: 91 days (92 in leap years)
Apr 1 to Jun 30: 91 days
Jul 1 to Sep 30: 92 days
Oct 1 to Dec 30: 91 days
(As opposed to to 90,91,92,92 days)