# Kalender Gregorius

**Kalender Gregorius** adolah kalender nan digunoan di sabagian gadang dunia. Kalender ko mulai balaku pado bulan Oktober 1582 sasudah bulla kapausan *Inter gravissimas* nan dikaluaan dek Paus Gregorius XIII, nan mangelannyo sabagai modifikasi jo pangganti kalender Julius. Parubahan utamonyo iolah manampekan tahun kabisat saketek babedo untuak mambuek tahun kalender rato-rato manjadi 365,2425 hari, bukan 365,25 hari takah kalender Julius, sahinggo labiah mandakeki tahun “tropis" atau matoari 365,2422 hari nan ditantuan dek revolusi Bumi mangaliliangi Matoari.

Aturan tahun kabisat manyatoan bahwasannyo satiok tahun nan habih dibagi ampek adolah tahun kabisat, kacuali tahun nan habih dibagi 100 (kacuali jikok habih dibagi 400). Misalnyo, tahun 1800 dan 1900 bukan tahun kabisat, tapi 1600 jo 2000 adolah tahun kabisat.

Kalender Gregorius dibuek untuak mamelokan kasalahan kalender Julius nan panjang bana, sahinggo manyababan pageseran tahadap ekuinoks jo panantuan Paskah. Reformasi ko mailangan salisiah nan malompeki 10 hari pado tahun 1582 jo manyasuaian pahituangan tahun sarato siklus bulan.

Awalnyo digunoan di nagara Katolik, kalender ko kamudian diadobsi sacaro batahap dek nagara lain, maskipun sabagian gareja Ortodoks masih manggunoan kalender Julius untuak kaparaluan kaagamoan.

## Rujuakan

## Bibliografi

* Blackburn, Bonnie; Holford-Strevens, Leofranc (1999). *The Oxford Companion to the Year*. Oxford University Press. ISBN 9780192142313.  .
* Blegen, Carl W. (25 December 2013). Vogeikoff-Brogan, Natalia, ed. "An Odd Christmas". From the Archivist's Notebook. Diakses tanggal 1 April 2018.
* Bond, John James (1875). "Commencement of the Year, on the 1st of January or otherwise, and adoption of the Gregorian Calendar". *Handy Book of Rules and Tables for Verifying Dates With the Christian Era Giving an Account of the Chief Eras and Systems Used by Various Nations...*. London: George Bell & Sons.
* Carabias Torres, A. M (2012) (dalam bahaso es). *Salamanca y la medida del tiempo*. Salamanca: Ediciones Universidad de Salamanca.
* Dershowitz, D.; Reingold, E. M (2008). *Calendrical Calculations* (edisi ke-3rd). Cambridge: Cambridge University Press.
* Gregory XIII (1582). *Inter Gravissimas*.
* Meeus, J.; Savoie, D. (1992). "The history of the tropical year". *Journal of the British Astronomical Association*. **102** (1): 40–42. Bibcode:1992JBAA..102...40M.
* Moyer, Gordon (1983). "Aloisius Lilius and the *Compendium Novae Rationis Restituendi Kalendarium*". di dalam Coyne, G. V.; Hoskin, M. A.; Pedersen, O.. Gregorian Reform of the Calendar: Proceedings of the Vatican Conference to Commemorate its 400th Anniversary. Vatican City: Pontifical Academy of Sciences, Specolo Vaticano. pp. 171–188.
* Poole, Robert (1995). "'Give us our eleven days!': calendar reform in eighteenth-century England" (PDF). *Past & Present*. Oxford Academic (149): 95–139. doi:10.1093/past/149.1.95. JSTOR 651100. Diakses tanggal 4 December 2020.
* Richards, E. G. (1998). *Mapping Time: The Calendar and its History*. Oxford University Press. Bibcode: 1998mtch.book.....R.
* Richards, E. G. (2013). "Calendars". *Explanatory Supplement to the Astronomical Almanac* (edisi ke-3rd). Mill Valley CA: University Science Books. pp. 585–624. ISBN 978-1-891389-85-6.
* *Explanatory Supplement to the Astronomical Almanac* (edisi ke-2nd). Sausalito, CA: University Science Books. 13 Juni 1992. Bibcode: 1992esaa.book.....S.
* Swerdlow, N. M. (1986). "The Length of the Year in the Original Proposal for the Gregorian Calendar". *Journal for the History of Astronomy*. **17** (49): 109–118. Bibcode:1986JHA....17..109S. doi:10.1177/002182868601700204.  Parameter `|s2cid=` yang tidak diketahui akan diabaikan (bantuan)
* Walker, G. W.. *Popular Astronomy* **53** (6): 162–178, 218–232.
* Ziggelaar, A. (1983). "The Papal Bull of 1582 Promulgating a Reform of the Calendar". di dalam Coyne, G. V.; Hoskin, M. A.; Pedersen, O.. Gregorian Reform of the Calendar: Proceedings of the Vatican Conference to Commemorate its 400th Anniversary. Vatican City: Pontifical Academy of Sciences, Specolo Vaticano. pp. 201–239.