table showing days, weeks, and months of a year; a list or schedule: Put the meeting on your calendar.

Not to be confused with:

calender – a machine that presses cloth or paper through rollers: The laundry used a calender to press the sheets.[1]
colander – a sieve or strainer: He used a colander to drain the pasta.[2]

Abused, Confused, & Misused Words by Mary Embree Copyright © 2007, 2013 by Mary Embree



n.1. Any of various systems of reckoning time in which the beginning, length, and divisions of a year are defined, sometimes along with multiyear cycles.

2. A table showing the months, weeks, and days in at least one specific year.

3. A schedule of events.

4. An ordered list of matters to be considered: the bills on a legislative calendar.

5. Chiefly British A catalog of a university.

tr.v. cal·en·dared, cal·en·dar·ing, cal·en·dars To enter in a calendar; schedule.

[Middle English calender, from Old French calendier, from Late Latin kalendārium, from Latin, account book, from kalendae, calends (from the fact that monthly interest was due on the calends); see kelə-[3] in Indo-European roots[4].]


The Gregorian calendar is now in use as the civil calendar throughout most of the world. The Jewish calendar is the official calendar of the Jewish religious community. The Islamic calendar is the official calendar in many Muslim countries. Each calendar listed below begins with the first month of the year and includes the number of days each month contains. Many months have a variable number of days, as described below.

The Gregorian calendar, introduced in 1582 by Pope Gregory XIII, is a corrected form of the Julian calendar. It is based on a solar year of 365 days. Every fourth year is a leap year of 366 days except for centenary years not evenly divisible by 400.The Jewish year consists of twelve months defined by lunar cycles, with some years having a thirteenth month so that seasonal festivals stay aligned with the solar year. For religious purposes Nisan is the first month, but the New Year is celebrated in Tishri.The Islamic calendar is based on the lunar year and contains 354 or 355 days. The number of days in each month varies with the lunar cycle. The beginning of the year retrogresses through the solar year, completing a full cycle every 32.5 years.
MonthsNumber of DaysMonthsNumber of DaysMonthsNumber of Days
January31Nisan(Mar-Apr)30Muharram29 or 30
February28 or 29Iyar(Apr-May)29Safar29 or 30
March31Sivan(May-Jun)30Rabi I29 or 30
April30Tammuz(Jun-Jul)29Rabi II29 or 30
May31Av(Jul-Aug)30Jumada I29 or 30
June30Elul(Aug-Sep)29Jumada II29 or 30
July31Tishri(Sep-Oct)30Rajab29 or 30
August31Heshvan(Oct-Nov)29 or 30Shaʔban29 or 30
September30Kislev(Nov-Dec)29 or 30Ramadan29 or 30
October31Tevet(Dec-Jan)29Shawwal29 or 30
November30Shevat(Jan-Feb)30Dhu’l-Qa’dah29 or 30
December31Adar(Feb-Mar)29 or 30Dhu’l-Hijjah29 or 30
Adar Sheni(leap year only)29

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.



n2. a table showing any such arrangement, esp as applied to one or more successive years

3. a list, register, or schedule of social events, pending court cases, appointments, etc

vb (tr) to enter in a calendar; schedule; register

[C13: via Norman French from Medieval Latin kalendārium account book, from Kalendae the calends, when interest on debts became due]

calendrical, caˈlendric adj

Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈkæl ən dər) n.

1. a table or register with the days of each month and week in a year.

2. any of various systems of reckoning time, esp. with reference to the beginning, length, and divisions of the year, as the Gregorian calendar or the Julian calendar.

3. a list or register, esp. one arranged chronologically, as of appointments, cases to be tried in court, or bills to be considered by a legislature.

4. Obs. a guide or example.

v.t. 5. to enter in a calendar; register.

[1175–1225; Middle English calender calendārium account book, derivative of Calend(ae) calends[5] (when debts were due)]

ca•len•dri•cal (kəˈlɛn drɪ kəl) ca•len′dric, adj.

Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.


a flgure-of-eight-shaped scale, for showing the declination of the sun and the equation of time for every day of the year. — analemmatic, adj.

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