Date of Easter (English Wikipedia)

Kothe, Jochen. "Berechnung des Osterfestes". Astronomische Abhandlungen [Astronomical Treatises] (in German). Archived from the original on 9 July 2012. Retrieved 9 August 2017.
Kothe, Jochen. "Berichtigung ze dem aufsatze". Astronomische Abhandlungen [Astronomical Treatises] (in German). Archived from the original on 12 July 2012. Retrieved 9 August 2017.

bluewaterarts.com

Pope Gregory XIII (24 February 1582). "Inter Gravissimas". Archived from the original on 13 February 2006. Retrieved 9 August 2017.

books.google.com

Although this is the dating of Augustalis by Bruno Krusch, see arguments for a 5th century date in Mosshammer 2008, pp. 217, 227–228. Mosshammer, Alden A. (2008). The Easter Computus and the Origins of the Christian Era. Oxford: University Press. ISBN 978-0-19-954312-0. Archived from the original on 9 April 2023. Retrieved 9 June 2021.
For confirmation of Dionysius's role see Blackburn & Holford-Strevens 1999, p. 794. Blackburn, Bonnie J.; Holford-Strevens, Leofranc (1999). The Oxford Companion to the Year. Oxford University Press. ISBN 978-0-19-214231-3.
"the [Golden Number] of a year AD is found by adding one, dividing by 19, and taking the remainder (treating 0 as 19)."(Blackburn & Holford-Strevens 1999, p. 810). Blackburn, Bonnie J.; Holford-Strevens, Leofranc (1999). The Oxford Companion to the Year. Oxford University Press. ISBN 978-0-19-214231-3.
Can be verified by using Blackburn & Holford-Strevens 1999, p. 825, Table 7. Blackburn, Bonnie J.; Holford-Strevens, Leofranc (1999). The Oxford Companion to the Year. Oxford University Press. ISBN 978-0-19-214231-3.
Traditionally in the Christian West, this situation was handled by extending the first 29-day lunar month of the year to 30 days, and beginning the following lunar month one day later than otherwise if it was due to begin before the leap day.(Blackburn & Holford-Strevens 1999, p. 813). Blackburn, Bonnie J.; Holford-Strevens, Leofranc (1999). The Oxford Companion to the Year. Oxford University Press. ISBN 978-0-19-214231-3.
Ayto 2009, p. 123. Ayto, John, ed. (2009). Oxford Dictionary of English Idioms (3rd ed.). OUP Oxford. p. 123. ISBN 978-0-19-954378-6.
Peterson 2015, p. 468. Peterson, Michael D. (2015). "Fasting: Eastern Christian". In Johnston, William M.; Kleinhenz, Christopher (eds.). Encyclopaedia of Monasticism. Routledge. p. 468. ISBN 978-1-57958-090-2. Archived from the original on 9 April 2023. Retrieved 21 March 2023.
Bede 1999, p. xviii. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Bede 1999, pp. xviii–xx. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Bede 1999, p. xx. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Bede 1999, p. xxxvi. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Bede 1999, pp. 425–426, Appendix 4: A Note on the Term Computus. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Bede 1999, pp. xxxv–xxxvii. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Bede 1999, pp. xxxviii–xl. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Declercq 2000, p. 80. Declercq, Georges (2000). Anno Domini: The Origins of the Christian Era. Isd. ISBN 978-2-503-51050-7. Archived from the original on 9 April 2023. Retrieved 14 December 2020.
Declercq 2000, p. 97. Declercq, Georges (2000). Anno Domini: The Origins of the Christian Era. Isd. ISBN 978-2-503-51050-7. Archived from the original on 9 April 2023. Retrieved 14 December 2020.
Declercq 2000, p. 99. Declercq, Georges (2000). Anno Domini: The Origins of the Christian Era. Isd. ISBN 978-2-503-51050-7. Archived from the original on 9 April 2023. Retrieved 14 December 2020.
Blackburn & Holford-Strevens 1999, p. 793. Blackburn, Bonnie J.; Holford-Strevens, Leofranc (1999). The Oxford Companion to the Year. Oxford University Press. ISBN 978-0-19-214231-3.
Bede 1943, p. 90: The letter [of Cummian] is at once a report and an apology or justification to Abbot Seghine at Iona of a synod held at Campus Lenis (Magh-Lene), where the Easter question was considered. The direct result of the synod was an alteration in the observance among the southern Irish and the adoption of the Alexandrian reckoning. Bede (1943). Charles Williams Jones (ed.). Bedae Opera de Temporibus. Mediaeval Academy of America. Archived from the original on 9 April 2023. Retrieved 9 June 2021.
Bede 1999, pp. lix–lxiii. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Bede 1999, pp. xlvi. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Clavius 1603. Clavius, Christopher (1603). Romani calendarij à Gregorio XIII. P. M. restituti explicatio. Archived from the original on 9 April 2023. Retrieved 16 November 2021. In the fifth volume of Opera Mathematica, Mainz, 1612. Opera Mathematica of Christoph Clavius includes page images of the Six Canons and the Explicatio (Go to page: Roman Calendar of Gregory XIII).
Dershowitz & Reingold 2008, pp. 113–117. Dershowitz, Nachum; Reingold, Edward M. (2008). Calendrical Calculations. Cambridge University Press. ISBN 978-0-521-88540-9. Archived from the original on 9 April 2023. Retrieved 14 December 2020.
Mosshammer 2008, p. 76. Mosshammer, Alden A. (2008). The Easter Computus and the Origins of the Christian Era. Oxford: University Press. ISBN 978-0-19-954312-0. Archived from the original on 9 April 2023. Retrieved 9 June 2021.
Dershowitz & Reingold 2008, pp. 114–115. Dershowitz, Nachum; Reingold, Edward M. (2008). Calendrical Calculations. Cambridge University Press. ISBN 978-0-521-88540-9. Archived from the original on 9 April 2023. Retrieved 14 December 2020.
Dershowitz & Reingold 2008, p. 114. Dershowitz, Nachum; Reingold, Edward M. (2008). Calendrical Calculations. Cambridge University Press. ISBN 978-0-521-88540-9. Archived from the original on 9 April 2023. Retrieved 14 December 2020.
Grotefend 1891. Grotefend, Hermann (1891). Zeitrechnung des deutschen Mittelalters und der Neuzeit. Hahn. Archived from the original on 9 April 2023. Retrieved 27 November 2020.
Dershowitz & Reingold 2008, p. 117. Dershowitz, Nachum; Reingold, Edward M. (2008). Calendrical Calculations. Cambridge University Press. ISBN 978-0-521-88540-9. Archived from the original on 9 April 2023. Retrieved 14 December 2020.
Paucker, Georg (1837). "Die Osterrechnung oder Vorschlag zur Einführung eines kirchlichen Kalenders und Osterkanons". Riga: Eduard Frantzen's Buchhandlung. p. 59. Archived from the original on 9 April 2023. Retrieved 6 September 2022.
Byrhtferth of Ramsey 1995, pp. 136–7, 320–322. Byrhtferth of Ramsey (1995). Lapidge, Michael; Peter Stuart Baker (eds.). Byrhtferth's Enchiridion. Early English Text Society. ISBN 978-0-19-722416-8. Archived from the original on 9 April 2023. Retrieved 9 June 2021.
Domus Quaedam Vetus 2009, p. 151. Domus Quaedam Vetus (July 2009). Carmina Medii Aevi Maximam Partem Inedita. BiblioBazaar. ISBN 978-1-110-75828-9.
Bede 1999, pp. xlvii. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Nothaft 2018, pp. 275–277. Nothaft, C. Philipp E. (2018). Scandalous Error: Calendar Reform and Calendrical Astronomy in Medieval Europe. Oxford University Press. ISBN 978-0-19-879955-9. Archived from the original on 9 April 2023. Retrieved 27 November 2020.
Lange 1928. Lange, Ludwig (1928). "Paradoxe" Osterdaten im Gregorianischen Kalender und ihre Bedeutung für die moderne Kalender reform von Ludwig Lange. Vorgelegt von Eduard Schwartz am 7. Juli 1928. Bayer. Akad. d. Wissenschaften. Archived from the original on 9 April 2023. Retrieved 27 November 2020.
A New York correspondent (20 April 1876). "To find Easter". Nature: 487.
Butcher 1877, p. 225. Butcher, Samuel (1877). The Ecclesiastical calendar: its theory and construction. Dublin: Hodges, Foster and Figgis. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
O'Beirne 1961, p. 828. O'Beirne, T H (30 March 1961). "How ten divisions lead to Easter". New Scientist. 9 (228): 828. Archived from the original on 9 April 2023. Retrieved 7 June 2021.

ccel.org

Anatolius, Book 7, Chapter 33. Anatolius of Laodicea, "Paschal Canons quoted by Eusebius", The Ecclesiastical History of Eusebius, archived from the original on 14 April 2021, retrieved 13 April 2021.

cyprusactionnetwork.org

Kekis, Theoharis. "The Orthodox Church Calendar" (PDF). Cyprus Action Network of America. Archived from the original (PDF) on 26 November 2012. Retrieved 11 March 2012.

demon.co.uk

merlyn.demon.co.uk

Stockton, J. R. "The Calculation of Easter Sunday after the Book of Common Prayer". Archived from the original on 7 September 2015. Retrieved 9 August 2017.

doi.org

Turner 1895, pp. 699–710. Turner, C.H. (1895). "The Paschal Canon of Anatolius of Laodicea". The English Historical Review. 10: 699–710. doi:10.1093/ehr/x.xl.699.
McCarthy 1996, pp. 285–320. McCarthy, Daniel (1996). "The Lunar and Paschal Tables of De ratione paschali Attributed to Anatolius of Laodicea". Archive for History of Exact Sciences. 49 (4): 285–320. Bibcode:1996AHES...49..285M. doi:10.1007/bf00374701. S2CID 120081352.
McCarthy 1993, pp. 204–224. McCarthy, Daniel (August 1993). "Easter principles and a fifth-century lunar cycle used in the British Isles". Journal for the History of Astronomy. 24 (3): 204–224. Bibcode:1993JHA....24..204M. doi:10.1177/002182869302400304. S2CID 115765809.
Swerdlow 1986, pp. 109–118. Swerdlow, Noel 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. S2CID 118491152.
Teres 1984, p. 178. Teres, Gustav (1984). "Time computations and Dionysius Exiguus". Journal for the History of Astronomy. 15 (3): 177–188. Bibcode:1984JHA....15..177T. doi:10.1177/002182868401500302. S2CID 117094612.
Bien 2004, pp. 439–452. Bien, Reinhold (July 2004). "Gauß and Beyond: The Making of Easter Algorithms". Archive for History of Exact Sciences. 58 (5): 439−452. Bibcode:2004AHES...58..439B. doi:10.1007/s00407-004-0078-5. S2CID 121657716.

eskimo.com

Book of Common Prayer. "Tables and Rules". Archived from the original on 27 May 2021. Retrieved 26 June 2021.

etymonline.com

Harper, Douglas. "epact". Online Etymology Dictionary.

gutenberg.org

Bede 1907, p. 193, Book III, Chapter XXV. Bede (1907) [731]. Bede's Ecclesiastical History of England. Translated by Sellar, A. M.; Giles, J. A. London: George Bell and Sons. Archived from the original on 12 May 2019. Retrieved 23 March 2019 – via Project Gutenberg.
Bede 1907, p. xxvii. Bede (1907) [731]. Bede's Ecclesiastical History of England. Translated by Sellar, A. M.; Giles, J. A. London: George Bell and Sons. Archived from the original on 12 May 2019. Retrieved 23 March 2019 – via Project Gutenberg.

gwdg.de

webdoc.sub.gwdg.de

"Gauß-CD". webdoc.sub.gwdg.de. Archived from the original on 6 December 2016. Retrieved 9 August 2017.

harvard.edu

ui.adsabs.harvard.edu

McCarthy 1996, pp. 285–320. McCarthy, Daniel (1996). "The Lunar and Paschal Tables of De ratione paschali Attributed to Anatolius of Laodicea". Archive for History of Exact Sciences. 49 (4): 285–320. Bibcode:1996AHES...49..285M. doi:10.1007/bf00374701. S2CID 120081352.
McCarthy 1993, pp. 204–224. McCarthy, Daniel (August 1993). "Easter principles and a fifth-century lunar cycle used in the British Isles". Journal for the History of Astronomy. 24 (3): 204–224. Bibcode:1993JHA....24..204M. doi:10.1177/002182869302400304. S2CID 115765809.
Shields 1924, pp. 407–411. Shields, Miriam Nancy (1924). "The new calendar of the Eastern churches". Popular Astronomy. 32: 407–411. Bibcode:1924PA.....32..407S.
Davison, Michael E. (1980). "The Frequency Distribution of the Dates of Easter". The Irish Astronomical Journal. 14: 156–164. Bibcode:1980IrAJ...14..156D. Archived from the original on 9 April 2023. Retrieved 17 May 2022.
Walker, George W. (1944). "Rare Dates for Easter". Popular Astronomy. No. 52. pp. 139–142. Bibcode:1944PA.....52..139W. Archived from the original on 9 April 2023. Retrieved 17 May 2022.
de Kort 1949, pp. 109–116. de Kort, J. J. M. A. (September 1949). "Astronomical appreciation of the Gregorian calendar". Ricerche Astronomiche. 2 (6): 109–116. Bibcode:1949RA......2..109D.
Swerdlow 1986, pp. 109–118. Swerdlow, Noel 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. S2CID 118491152.
Teres 1984, p. 178. Teres, Gustav (1984). "Time computations and Dionysius Exiguus". Journal for the History of Astronomy. 15 (3): 177–188. Bibcode:1984JHA....15..177T. doi:10.1177/002182868401500302. S2CID 117094612.
Bien 2004, pp. 439–452. Bien, Reinhold (July 2004). "Gauß and Beyond: The Making of Easter Algorithms". Archive for History of Exact Sciences. 58 (5): 439−452. Bibcode:2004AHES...58..439B. doi:10.1007/s00407-004-0078-5. S2CID 121657716.
Downing 1916, pp. 215–219. Downing, A. M. W. (May 1916). "The date of Easter". The Observatory. 39: 215–219. Bibcode:1916Obs....39..215D.
"Letters to the Editor". Journal of the British Astronomical Association. 88: 91. December 1977. Bibcode:1977JBAA...88...87.

henk-reints.nl

See especially the first, second, fourth, and sixth canon, and the calendarium
Audette, Rodolphe (9 December 2007). "Dionysius Exiguus – Liber de Paschate". Archived from the original on 15 April 2021. Retrieved 26 June 2021.

loria.fr

members.loria.fr

Roegel, Denis (24 November 2004). "The missing new moon of A.D. 16399 and other anomalies of the Gregorian calendar" (PDF). Archived (PDF) from the original on 25 February 2021. Retrieved 26 June 2021.

oikoumene.org

Towards a Common Date for Easter, Aleppo, Syria: World Council of Churches/Middle East Council of Churches Consultation, 10 March 1997, archived from the original on 30 March 2018.

oremus.org

bible.oremus.org

revradiotowerofsong.org

Re-vision Radio's Tower of Song. "The Many Easters & Eostres for the Many: A Choice of Hallelujahs". Archived from the original on 16 April 2021. Retrieved 26 June 2021.

semanticscholar.org

api.semanticscholar.org

McCarthy 1996, pp. 285–320. McCarthy, Daniel (1996). "The Lunar and Paschal Tables of De ratione paschali Attributed to Anatolius of Laodicea". Archive for History of Exact Sciences. 49 (4): 285–320. Bibcode:1996AHES...49..285M. doi:10.1007/bf00374701. S2CID 120081352.
McCarthy 1993, pp. 204–224. McCarthy, Daniel (August 1993). "Easter principles and a fifth-century lunar cycle used in the British Isles". Journal for the History of Astronomy. 24 (3): 204–224. Bibcode:1993JHA....24..204M. doi:10.1177/002182869302400304. S2CID 115765809.
Swerdlow 1986, pp. 109–118. Swerdlow, Noel 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. S2CID 118491152.
Teres 1984, p. 178. Teres, Gustav (1984). "Time computations and Dionysius Exiguus". Journal for the History of Astronomy. 15 (3): 177–188. Bibcode:1984JHA....15..177T. doi:10.1177/002182868401500302. S2CID 117094612.
Bien 2004, pp. 439–452. Bien, Reinhold (July 2004). "Gauß and Beyond: The Making of Easter Algorithms". Archive for History of Exact Sciences. 58 (5): 439−452. Bibcode:2004AHES...58..439B. doi:10.1007/s00407-004-0078-5. S2CID 121657716.

tertullian.org

Schaff, Philip; Wace, Henry, eds. (1890), The Synodal Letter, Nicene and Post-Nicene Fathers: Second Series, vol. 14, The Seven Ecumenical Councils, Grand Rapids, Michigan, U.S.: Eerdmans Pub Co., pp. 112–114, ISBN 0-8028-8129-7, archived from the original on 28 September 2020, retrieved 4 July 2020

timeanddate.com

"Seasons calculator". Time and Date AS. 2014. Archived from the original on 23 March 2019. Retrieved 23 March 2019.

tufts.edu

perseus.tufts.edu

ἐπακτός. Liddell, Henry George; Scott, Robert; A Greek–English Lexicon at the Perseus Project.

uni-goettingen.de

gdz.sub.uni-goettingen.de

Kothe, Jochen. "Berechnung des Osterfestes". Astronomische Abhandlungen [Astronomical Treatises] (in German). Archived from the original on 9 July 2012. Retrieved 9 August 2017.
Kothe, Jochen. "Berichtigung ze dem aufsatze". Astronomische Abhandlungen [Astronomical Treatises] (in German). Archived from the original on 12 July 2012. Retrieved 9 August 2017.

utoronto.ca

individual.utoronto.ca

"The Length of the Seasons". U. Toronto. Canada. Archived from the original on 20 January 2018. Retrieved 31 January 2018.
"Mean Northward Equinoctial Year Length" (PDF). U. Toronto. Canada. Archived (PDF) from the original on 5 March 2016. Retrieved 31 January 2018.

uu.nl

webspace.science.uu.nl

van Gent 2019. van Gent, Robert (2019), Anomalous Easter Sunday Dates in the 18th and early 19th Century, Utrecht University, archived from the original on 1 August 2020, retrieved 23 July 2019.

web.archive.org

Although this is the dating of Augustalis by Bruno Krusch, see arguments for a 5th century date in Mosshammer 2008, pp. 217, 227–228. Mosshammer, Alden A. (2008). The Easter Computus and the Origins of the Christian Era. Oxford: University Press. ISBN 978-0-19-954312-0. Archived from the original on 9 April 2023. Retrieved 9 June 2021.
Peterson 2015, p. 468. Peterson, Michael D. (2015). "Fasting: Eastern Christian". In Johnston, William M.; Kleinhenz, Christopher (eds.). Encyclopaedia of Monasticism. Routledge. p. 468. ISBN 978-1-57958-090-2. Archived from the original on 9 April 2023. Retrieved 21 March 2023.
Bede 1999, p. xviii. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Bede 1999, pp. xviii–xx. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Bede 1999, p. xx. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Bede 1999, p. xxxvi. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Bede 1999, pp. 425–426, Appendix 4: A Note on the Term Computus. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Bede 1999, pp. xxxv–xxxvii. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Anatolius, Book 7, Chapter 33. Anatolius of Laodicea, "Paschal Canons quoted by Eusebius", The Ecclesiastical History of Eusebius, archived from the original on 14 April 2021, retrieved 13 April 2021.
Bede 1999, pp. xxxviii–xl. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Declercq 2000, p. 80. Declercq, Georges (2000). Anno Domini: The Origins of the Christian Era. Isd. ISBN 978-2-503-51050-7. Archived from the original on 9 April 2023. Retrieved 14 December 2020.
Declercq 2000, p. 97. Declercq, Georges (2000). Anno Domini: The Origins of the Christian Era. Isd. ISBN 978-2-503-51050-7. Archived from the original on 9 April 2023. Retrieved 14 December 2020.
Declercq 2000, p. 99. Declercq, Georges (2000). Anno Domini: The Origins of the Christian Era. Isd. ISBN 978-2-503-51050-7. Archived from the original on 9 April 2023. Retrieved 14 December 2020.
Audette, Rodolphe (9 December 2007). "Dionysius Exiguus – Liber de Paschate". Archived from the original on 15 April 2021. Retrieved 26 June 2021.
Bede 1907, p. 193, Book III, Chapter XXV. Bede (1907) [731]. Bede's Ecclesiastical History of England. Translated by Sellar, A. M.; Giles, J. A. London: George Bell and Sons. Archived from the original on 12 May 2019. Retrieved 23 March 2019 – via Project Gutenberg.
Bede 1943, p. 90: The letter [of Cummian] is at once a report and an apology or justification to Abbot Seghine at Iona of a synod held at Campus Lenis (Magh-Lene), where the Easter question was considered. The direct result of the synod was an alteration in the observance among the southern Irish and the adoption of the Alexandrian reckoning. Bede (1943). Charles Williams Jones (ed.). Bedae Opera de Temporibus. Mediaeval Academy of America. Archived from the original on 9 April 2023. Retrieved 9 June 2021.
Bede 1907, p. xxvii. Bede (1907) [731]. Bede's Ecclesiastical History of England. Translated by Sellar, A. M.; Giles, J. A. London: George Bell and Sons. Archived from the original on 12 May 2019. Retrieved 23 March 2019 – via Project Gutenberg.
Bede 1999, pp. lix–lxiii. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Kekis, Theoharis. "The Orthodox Church Calendar" (PDF). Cyprus Action Network of America. Archived from the original (PDF) on 26 November 2012. Retrieved 11 March 2012.
Re-vision Radio's Tower of Song. "The Many Easters & Eostres for the Many: A Choice of Hallelujahs". Archived from the original on 16 April 2021. Retrieved 26 June 2021.
"Seasons calculator". Time and Date AS. 2014. Archived from the original on 23 March 2019. Retrieved 23 March 2019.
van Gent 2019. van Gent, Robert (2019), Anomalous Easter Sunday Dates in the 18th and early 19th Century, Utrecht University, archived from the original on 1 August 2020, retrieved 23 July 2019.
Towards a Common Date for Easter, Aleppo, Syria: World Council of Churches/Middle East Council of Churches Consultation, 10 March 1997, archived from the original on 30 March 2018.
Bede 1999, pp. xlvi. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Clavius 1603. Clavius, Christopher (1603). Romani calendarij à Gregorio XIII. P. M. restituti explicatio. Archived from the original on 9 April 2023. Retrieved 16 November 2021. In the fifth volume of Opera Mathematica, Mainz, 1612. Opera Mathematica of Christoph Clavius includes page images of the Six Canons and the Explicatio (Go to page: Roman Calendar of Gregory XIII).
Dershowitz & Reingold 2008, pp. 113–117. Dershowitz, Nachum; Reingold, Edward M. (2008). Calendrical Calculations. Cambridge University Press. ISBN 978-0-521-88540-9. Archived from the original on 9 April 2023. Retrieved 14 December 2020.
Mosshammer 2008, p. 76. Mosshammer, Alden A. (2008). The Easter Computus and the Origins of the Christian Era. Oxford: University Press. ISBN 978-0-19-954312-0. Archived from the original on 9 April 2023. Retrieved 9 June 2021.
Dershowitz & Reingold 2008, pp. 114–115. Dershowitz, Nachum; Reingold, Edward M. (2008). Calendrical Calculations. Cambridge University Press. ISBN 978-0-521-88540-9. Archived from the original on 9 April 2023. Retrieved 14 December 2020.
Dershowitz & Reingold 2008, p. 114. Dershowitz, Nachum; Reingold, Edward M. (2008). Calendrical Calculations. Cambridge University Press. ISBN 978-0-521-88540-9. Archived from the original on 9 April 2023. Retrieved 14 December 2020.
Grotefend 1891. Grotefend, Hermann (1891). Zeitrechnung des deutschen Mittelalters und der Neuzeit. Hahn. Archived from the original on 9 April 2023. Retrieved 27 November 2020.
Davison, Michael E. (1980). "The Frequency Distribution of the Dates of Easter". The Irish Astronomical Journal. 14: 156–164. Bibcode:1980IrAJ...14..156D. Archived from the original on 9 April 2023. Retrieved 17 May 2022.
Dershowitz & Reingold 2008, p. 117. Dershowitz, Nachum; Reingold, Edward M. (2008). Calendrical Calculations. Cambridge University Press. ISBN 978-0-521-88540-9. Archived from the original on 9 April 2023. Retrieved 14 December 2020.
Walker, George W. (1944). "Rare Dates for Easter". Popular Astronomy. No. 52. pp. 139–142. Bibcode:1944PA.....52..139W. Archived from the original on 9 April 2023. Retrieved 17 May 2022.
Roegel, Denis (24 November 2004). "The missing new moon of A.D. 16399 and other anomalies of the Gregorian calendar" (PDF). Archived (PDF) from the original on 25 February 2021. Retrieved 26 June 2021.
Paucker, Georg (1837). "Die Osterrechnung oder Vorschlag zur Einführung eines kirchlichen Kalenders und Osterkanons". Riga: Eduard Frantzen's Buchhandlung. p. 59. Archived from the original on 9 April 2023. Retrieved 6 September 2022.
"The Length of the Seasons". U. Toronto. Canada. Archived from the original on 20 January 2018. Retrieved 31 January 2018.
"Mean Northward Equinoctial Year Length" (PDF). U. Toronto. Canada. Archived (PDF) from the original on 5 March 2016. Retrieved 31 January 2018.
Book of Common Prayer. "Tables and Rules". Archived from the original on 27 May 2021. Retrieved 26 June 2021.
Stockton, J. R. "The Calculation of Easter Sunday after the Book of Common Prayer". Archived from the original on 7 September 2015. Retrieved 9 August 2017.
Pope Gregory XIII (24 February 1582). "Inter Gravissimas". Archived from the original on 13 February 2006. Retrieved 9 August 2017.
Schaff, Philip; Wace, Henry, eds. (1890), The Synodal Letter, Nicene and Post-Nicene Fathers: Second Series, vol. 14, The Seven Ecumenical Councils, Grand Rapids, Michigan, U.S.: Eerdmans Pub Co., pp. 112–114, ISBN 0-8028-8129-7, archived from the original on 28 September 2020, retrieved 4 July 2020
Byrhtferth of Ramsey 1995, pp. 136–7, 320–322. Byrhtferth of Ramsey (1995). Lapidge, Michael; Peter Stuart Baker (eds.). Byrhtferth's Enchiridion. Early English Text Society. ISBN 978-0-19-722416-8. Archived from the original on 9 April 2023. Retrieved 9 June 2021.
Bede 1999, pp. xlvii. Bede (1999). The Reckoning of Time. Translated by Faith Wallis. Liverpool University Press. ISBN 978-0-85323-693-1. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
Nothaft 2018, pp. 275–277. Nothaft, C. Philipp E. (2018). Scandalous Error: Calendar Reform and Calendrical Astronomy in Medieval Europe. Oxford University Press. ISBN 978-0-19-879955-9. Archived from the original on 9 April 2023. Retrieved 27 November 2020.
Lange 1928. Lange, Ludwig (1928). "Paradoxe" Osterdaten im Gregorianischen Kalender und ihre Bedeutung für die moderne Kalender reform von Ludwig Lange. Vorgelegt von Eduard Schwartz am 7. Juli 1928. Bayer. Akad. d. Wissenschaften. Archived from the original on 9 April 2023. Retrieved 27 November 2020.
"Gauß-CD". webdoc.sub.gwdg.de. Archived from the original on 6 December 2016. Retrieved 9 August 2017.
Butcher 1877, p. 225. Butcher, Samuel (1877). The Ecclesiastical calendar: its theory and construction. Dublin: Hodges, Foster and Figgis. Archived from the original on 9 April 2023. Retrieved 11 March 2016.
O'Beirne 1961, p. 828. O'Beirne, T H (30 March 1961). "How ten divisions lead to Easter". New Scientist. 9 (228): 828. Archived from the original on 9 April 2023. Retrieved 7 June 2021.

wikipedia.org

de.wikipedia.org

Although this is the dating of Augustalis by Bruno Krusch, see arguments for a 5th century date in Mosshammer 2008, pp. 217, 227–228. Mosshammer, Alden A. (2008). The Easter Computus and the Origins of the Christian Era. Oxford: University Press. ISBN 978-0-19-954312-0. Archived from the original on 9 April 2023. Retrieved 9 June 2021.

worldcat.org

Grumel 1958, p. 36. Grumel, V. (1958). La chronologie (in French). Paris: Presses Universitaires de France. OCLC 4260118.
Grumel 1958, p. 48. Grumel, V. (1958). La chronologie (in French). Paris: Presses Universitaires de France. OCLC 4260118.