Calender vs. Calendar: How to Spell It Right

If you are looking for the correct spelling, here it is: Calendar is the only correct spelling in standard English when referring to a system of organizing days.

The word ends in "-ar" (C-A-L-E-N-D-A-R). Spelling it as "calender" is universally considered a grammatical error in this context. If you struggle with this word, you are not alone—it is frequently misspelled because the ending sounds like "er", tricking writers into using the wrong vowel.

Notice how the word ends in "-ar" just like other time-related words like "year". While it sounds like "er", the suffix is strictly spelled with an "a".

To understand why the "a" is used, we have to look at Latin. The word comes from the Latin "calendarium", which translates to an account book or interest register. It is built from the root "calendae" or "kalendae", meaning the first day of the Roman month.

In ancient Rome, debts and interest were typically due on the first day of the month, so the "calendarium" was literally the book that tracked when payments were owed. Over time, the meaning shifted from tracking debts to tracking the days themselves. English adopted the word directly from Latin, preserving the "-ar" suffix.

Noah Webster, the father of American English spelling, intentionally simplified many words, but he left "calendar" alone because its Latin roots required the "a" to retain its historical structural meaning.

• Mark the calendar
• Check the calendar
• Sync calendars
• Calendar year
• Academic calendar
• Shared calendar

In daily conversation, "calendar" is often used to refer to both the physical paper datebook and the digital app on your phone. For example, telling a friend, "Let me check my calendar" means you need to look at your schedule. It is a fundamental word for organizing personal and social life.

• Don't forget to put my dentist appointment on the calendar.
• My paper calendar is the only way I remember birthdays.
• She checks her phone calendar before making dinner plans.
• I hung the new kitten calendar in the kitchen.
• Let's mark our vacation days on the calendar right now.

In academic writing, "calendar" is frequently used to describe historical systems of timekeeping or institutional schedules. For instance, "The transition from the Julian to the Gregorian calendar required a ten-day adjustment." It shows a formal, structural approach to time.

• The academic calendar runs from September to May.
• The Gregorian calendar was introduced by Pope Gregory XIII in 1582.
• Ancient civilizations relied on the lunar calendar to track seasons.
• The Mayan calendar is famous for its complex astronomical cycles.
• The Julian calendar was the predominant calendar in the Roman world.

In business emails, "calendar" is a cornerstone of scheduling language. Saying "I will send you a calendar invite" sounds much more professional and precise than saying "I will tell you when to meet." It implies a formal blocking of time on a shared system.

• Please check the corporate calendar before scheduling a board meeting.
• I will send you a calendar invite for the client presentation tomorrow.
• The CEO's calendar is completely booked for the rest of the week.
• Can you add the quarterly review to my digital calendar?
• The team uses a shared calendar to track who is in the office.