Calendar

April
Su Mo Tu We Th Fr Sa
1 2 3 4 5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30  
2025
Modern day Indonesian Gregorian calendar for a Catholic church
British calendar, 1851, gilt bronze and malachite, height: 20.3 cm, Metropolitan Museum of Art (New York City)

A calendar is a system of organizing days. This is done by giving names to periods of time, typically days, weeks, months and years.[1][2][3] A date is the designation of a single and specific day within such a system. A calendar is also a physical record (often paper) of such a system. A calendar can also mean a list of planned events, such as a court calendar, or a partly or fully chronological list of documents, such as a calendar of wills.

Periods in a calendar (such as years and months) are usually, though not necessarily, synchronized with the cycle of the sun or the moon.[4][5][6] The most common type of pre-modern calendar was the lunisolar calendar, a lunar calendar that occasionally adds one intercalary month to remain synchronized with the solar year over the long term.

  1. ^ "Calendars and their History". eclipse.gsfc.nasa.gov. Retrieved 12 March 2024.
  2. ^ Guo, Rongxing (16 May 2018). Human-Earth System Dynamics: Implications to Civilizations. Springer. p. 159. ISBN 978-981-13-0547-4.
  3. ^ Bond, Thomas; Hughes, Chris (3 December 2013). Singapore PSLE Mathematics Challenging Practice Solutions (Yellowreef). Yellowreef Limited. ISBN 978-0-7978-0222-3.
  4. ^ "Do menstrual and lunar cycles synchronize? What scientists say". www.medicalnewstoday.com. 12 February 2021. Retrieved 12 March 2024.
  5. ^ "Introduction to Calendars". aa.usno.navy.mil. Retrieved 12 March 2024.
  6. ^ "History – Ancient Egyptian Calendar" (PDF). Retrieved 12 March 2024.

© MMXXIII Rich X Search. We shall prevail. All rights reserved. Rich X Search