The following bibliography lists all sources consulted in preparing the article, as well as in compiling the feast days for the calendar applet. If you are interested in more detail about the general history of calendars and can read German, I strongly urge you to start with Ginzel, which despite its age remains indispensable. Another highly recommended work, which was published after I wrote the article, is Calendrical Calculations: The Millennium Edition, by Edward M. Reingold and Nachum Dershowitz (2001). (This is actually a 2nd edition, although they don't call it that.) Although its focus is computation of different calendars, it contains a huge amount of information on many different calendars, the information for many of which is not readily available in English.

The Alternative Service Book 1980: Services authorized for use in the Church of England in conjunction with The Book of Common Prayer together with The Liturgical Psalter. (1980).

The Book of Common Prayer and Administration of the Sacraments and other Rites and Ceremonies of the Church Together with the Psalter or Psalms of David According to the use of The Episcopal Church. (1979).

Bonniwell, William R., o.p. A History of the Dominican Liturgy, 1215-1945. (1945).

Brightman, F. E. The English Rite. Being a Synopsis of the Sources and Revisions of the Book of Common Prayer. 2 vols. 2nd ed, rev. (1921).

Bushwick, Nathan. Understanding the Jewish Calendar (1989).

Clagett, Marshall. Ancient Egyptian Science: vol. 2, Calendars, Clocks, and Astronomy (1995).

Eisenberg, Azriel. The Story of the Jewish Calendar. (1958).

Farmer, David Hugh. The Oxford Dictionary of the Saints. 3rd ed. (1992).

Ginzel, F. K. Handbuch der Mathematischen und Technischen Chronologie. 3 vols. (1906, 1911, 1914).

Gregorian Reform of the Calendar: Proceedings of the Vatican Conference to Commemorate its 400th Anniversary 1582-1982, eds. G. V. Coyne, S. J., M. A. Hoskin, and O. Pedersen (1983).

Hatchett, Marion J. Commentary on the American Prayer Book. (1995).

Missale ad usum percelebris ecclesiæ Herfordensis. (1874).

Hughes, Andrew. Medieval Manuscripts for Mass and Office: A Guide to their Organization and Terminology. (1982).

Jacobus de Voragine. The Golden Legend: Readings on the Saints. Trans. William Granger Ryan, 2 vols. (1993).

Jasper, R. C. D. and Paul F. Bradshaw. A Companion to the Alternative Service Book. (1986).

Johnson, Cuthbert, o.s.b., and Anthony Ward, s.m. Missale Romanum anno 1962 promulgatum. (1994).

Michels, Agness Kirsopp. The Calendar of the Roman Republic. (1967).

Mommsen, C. M. T. Römisches Staatsrecht, 3 vols. 3rd ed. (1887; reprt. 1952).

Neugebauer, O. A History of Ancient Mathematical Astronomy. 3 vols.

Meritt, Benjamin D. The Athenian Year. (1961).

Parker, Richard. Calendars: The Calendars of Ancient Egypt. (1950).

Parker, Richard A. and Waldo H. Dubberstein, Babylonian Chronology 626 BC - AD 75. (1956).

Pinches, T. G., J. N. Strassmaier, and A. J. Sachs. Late Babylonian Astronomical and Related Texts. (1955).

Pritchett, William, and Benjamin Meritt. The Chronology of Hellenistic Athens. (1940).

Pritchett, W. and O. Neugebauer. The Calendars of Athens. (1947).

Procter, Francis and Christopher Wordsworth. Breviarum ad usum insignis ecclesiae Sarum. 3 vols. (1879, 1882, 1886).

Van Goudoever, J. Biblical Calendars. (1959).

Weyns, N. I., ed. Sacramentarium Praemonstratense. (1968).

Zeller, Chr. "Kalender-Formeln", Acta Mathematica v. 9 (1886-7), pp. 131-6.