Calendar Wiki
Leap cycle
years per cycle leap days per cycle leap months per cycle leap weeks per cycle mean days per year Olympiad exception rule name / inventor
4 1 365.25 365 + ¼ Julian
19 5 7 365.26315789… N/A Meton
28 7 4 365.25 365 + ¼ (leap week) solar
33 8 365.(24) N/A Dee, Khayyám
62 15 11 365.24193548… N/A Sentinel
76 19 28 365.25 365 + ¼ Callippus
128 31 365.2421875 365 + ¼ – 1/128 von Mädler
132 32 365.(24) 365 + ¼ – 1/132
186 31 (45) 1 (33) 365.24193548… Butterfly
293 71 52 365.2423208… N/A Symmetrian
304 75 112 365.2467105… 365 + ¼ – 1/304 Hipparchos
334 81 123 365.24251497… N/A
353 130 365.24362606… N/A
372 137 365.24193548… N/A
391 144 365.24296675… N/A
400 97 71 365.2425 365 + ¼ – 1/100 + 1/400
= 365 + ¼ – 3/400
Gregorian
450 109 365.24(2) N/A Half orthodox
532 133 196 95 365.25 365 + ¼ Dionysian, Alexandrian
541 96 365.242144 N/A Hawaiian Slice
640 365.2421875 365 + ¼ – 1/128
656 159 365.2423780… 365 + ¼ – 5/656 ?
800 365.2425 365 + ¼ – 1/100 + 1/400
900 365.24(2) 365 + ¼ – 1/100 + 2/900 orthodox (revised Julian, Meletian, Milanković)
1689 622 365.2427471… N/A Goddess Lunar
2800 365 + ¼ – …
3200 775 365.2421875 365 + ¼ – 1/100 + 1/400 – 1/3200
6300 365 + ¼ – 1/100 + 2/900
6840 2519 365. 365 + ¼ – … Meyer-Palmen Solilunar Calendar

Parentheses show repeating digits, three dots (…) show continuing decimal fractions.

All items (37)