Is 四分の一 a natural way of referring to "a quarter" as in "a three-month duration"?


Is 四分の一 a natural way of referring to "a quarter" as in "a three-month
duration" (usually e.g. January-March, April-June, July-September, or October-
November) in Japanese?

[Japanese Stack Overflow](https://ja.stackoverflow.com/) uses 四分の一 on its
[users page](https://ja.stackoverflow.com/users?tab=Reputation&filter=quarter)
to mean "quarter" in this sense, but that looks kind of strange to me. I know
that 四分の一 means "one quarter" as in "one fourth" or "25%", but can it also be
used (without any other qualifiers, like 年の四分の一) to mean "a three-month
duration"?

Also, while we're here, what is the most natural way of referring to "a
quarter" in this sense? I'm aware of 四半期; is that the best option?




I agree that "四分の一" in the current _Users_ page of Japanese SE is weird.

四半期【しはんき】 is a technical term that is exclusively used in financial reports,
business plans, tax calculation, etc. Generally speaking, you can't use 四半期 in
casual/private situations, and you have to use "1年の4分の1" or "3か月" instead:

> 私は1年の4分の1をハワイで過ごします。  
>  = 私は1年のうち3か月をハワイで過ごします。  
>  ([*] 私は四半期をハワイで過ごします。 -- Weird)

However 四半期 can explicitly mean the year is delimited into four at the
beginning of months. Only by using 四半期 can people notice the current 四半期
started on October 1st, and the rep count for this 四半期 will end at the end of
2014. If we used "3か月" instead, people would interpret it as "the last 3
months", which is not the case.

So I think 四半期 is the best word that describes the SE's rule, although it may
look a bit stiff.




I agree that "四分の一" in the current _Users_ page of Japanese SE is weird.

四半期【しはんき】 is a technical term that is exclusively used in financial reports,
business plans, tax calculation, etc. Generally speaking, you can't use 四半期 in
casual/private situations, and you have to use "1年の4分の1" or "3か月" instead:

> 私は1年の4分の1をハワイで過ごします。  
>  = 私は1年のうち3か月をハワイで過ごします。  
>  ([*] 私は四半期をハワイで過ごします。 -- Weird)

However 四半期 can explicitly mean the year is delimited into four at the
beginning of months. Only by using 四半期 can people notice the current 四半期
started on October 1st, and the rep count for this 四半期 will end at the end of
2014. If we used "3か月" instead, people would interpret it as "the last 3
months", which is not the case.

So I think 四半期 is the best word that describes the SE's rule, although it may
look a bit stiff.

