# Year Division by Quarters: any terms to express halves of years or other parts of years?

Quarters divide years by four. I am looking for the terms dividing years by 2, 3 and 6.

Does there exists terms to express other parts of the years like quarters?

• Quarter is a generic term that means "divide in to four parts". It's not year specific, so use the same generic terms for the other fractions. – Matt E. Эллен Sep 15 '17 at 12:04
• @MattE.Эллен I cannot understand. Can I refer to half of year by Q1 and the second half of year by Q2? How does the reader know to which part of the year I mean? – hhh Sep 15 '17 at 12:10
• Downvoters would be recommended to be more constructive and leave a comment for improvement. – hhh Sep 15 '17 at 12:10
• Half, third, fifth, etc. – Matt E. Эллен Sep 15 '17 at 12:15
• @GEdgar I have seen H1/H2 - rarely But you'd want to explain them at first use in each document until they became established in context – Chris H Sep 15 '17 at 18:35

Yes, a quarter, or trimester is a period of 3 months (a quarter year).

Quarter: one fourth of a calendar or fiscal year: The bank sends out a statement each quarter.(http://www.dictionary.com/browse/quarter)

Trimester: a period of three or about three months; especially :any of three periods of approximately three months each into which a human pregnancy is divided https://www.merriam-webster.com/dictionary/trimester

A semester is a period of six months (half a year).

Semester :a period of six months https://www.merriam-webster.com/dictionary/semester

A bimester is a sixth of a year (two months).

Bimester :a period of two months

A tertile or quadrimester is four months (a third of a year).

Tertile: 1. (statistics) Either of the two points that divide an ordered distribution into three parts, each containing a third of the population. 2. (statistics) Any one of the three groups so divided. The first tertile results include January through April's revenues. https://en.wiktionary.org/wiki/tertile

• @hhh: to address the comment you added to your question- there are no other common terms in English for fractions of a year, like 1/5 year, 1/8 year, etc – ArchContrarian Sep 15 '17 at 12:21
• The above aren't all commonly used, either. Google Ngrams. – Edwin Ashworth Sep 15 '17 at 13:57
• @EdwinAshworth ... true, scratch 'other' in my last comment :) +1 – ArchContrarian Sep 15 '17 at 15:32
• @ArchContrarian the others divide the year into whole months (thus aren't really fractions if you think of the number of days). Fifths and eighths wouldn't, and would be of very limited use – Chris H Sep 15 '17 at 18:37
• @ChrisH ... that's true, but the question asks for words like 'quarter'. A quarter is invariably a period of three calendar months - not 1/4 of the days in the year. (Most years have a number of days not divisible by 4, anyway). Also, a 'fraction' can mean any part or subset, not just a precise arithmetical fraction. – ArchContrarian Sep 17 '17 at 21:22

In American business usage, particularly in financial reports, the year is divided into either months or quarters. No other division is common enough to have been given a name except for half. "That merger is scheduled to close in the first half."

"Semester" and "trimester" are primarily, perhaps exclusively, academic terms and refer to divisions of a "school year," which is not generally 365 days. I cannot remember hearing those terms ever used in a commercial or financial context.

It is of course possible to find special terms, but they are not in frequent use. What is usually done is to specify a fraction of a year or a number of days, weeks, or months. One might say "a third of a year" or "four months." Fractions using sixths or twelfths are rare. Most would say "seven months" rather than "seven twelfths of a year."

• "Semester" and "trimester" are primarily, perhaps exclusively, academic terms Well, "trimester" is also used for pregnancies. – GEdgar Sep 15 '17 at 21:15
• @ GEdgar. True but perhaps confusing with references to divisions of the solar year. "Trimester" in the obstetrical sense stands for one third of the duration of a normal human pregnancy, which is about three months, which is a quarter of a year. I should have said that "trimester" is primarily used in a certain restricted contexts to represent a third of a period, but it is seldom if ever used to designate a third of a solar year. Nevertheless, I overstated my case. – Jeff Morrow Sep 16 '17 at 0:46