Editing Calendar year (section)

==Quarter year==
{{anchor|Quarters}}
{{Redirect|Fourth quarter|the sports term|Comeback (sports)}}
The calendar year can be divided into four quarters,<ref>{{cite encyclopedia | url=https://www.merriam-webster.com/dictionary/calendar%20quarter |title=Calendar quarter |dictionary=Merriam-Webster (Merriam-Webster.com)|access-date= 23 December 2024}}</ref> often abbreviated as Q1, Q2, Q3, and Q4. Since they are three months each, they are also called [[Month|trimester]]s. In the [[Gregorian calendar]]:

* First quarter, Q1: January 1 – March 31 (90 days or 91 days in leap years)<ref>{{cite encyclopedia | url=https://dictionary.cambridge.org/us/dictionary/english/calendar-quarter |title=Calendar quarter |dictionary=Cambridge Business English Dictionary (Dictionary.Cambridge.org)|access-date= 23 December 2024}}</ref>
* Second quarter, Q2: April 1 – June 30 (91 days)
* Third quarter, Q3: July 1 – September 30 (92 days)
* Fourth quarter, Q4: October 1 – December 31 (92 days)

In some domains, weeks are preferred over months for scheduling and reporting, so they use quarters of exactly 13 weeks each, often following [[ISO week date]] conventions. One in five to six years has a 53rd week which is usually appended to the last quarter. It is then 98 days instead of 91 days long, which complicates comparisons.

In the [[Chinese calendar]], the quarters are traditionally associated with the 4 [[season]]s of the year:

* [[Spring (season)|Spring]]: 1st to 3rd month
* [[Summer]]: 4th to 6th month
* [[Autumn]]: 7th to 9th month
* [[Winter]]: 10th to 12th month