20002 222 2002 202
99 19 89 49
400 1100 600 900
King Greg I Lord Gregg Pope Gregory XIII Pope Gregory IX
1 day per year 6 days every century 3 days every 400 years 3 days every century
90 1100 150 900
Kepler St Greg Assisi St Bede
15 95 60 75
20 2000 40 200
Apr Jun Sep Nov Mar Jul Oct Dec Jan Apr Sep Dec Feb Jul Oct Nov