Apostrophes in Time Expressions

home▸sitemap▸common errors ▸apostrophes in time expressions

The Quick Answer

Apostrophes are used in time expressions. For example:

1 year's insurance
2 days' leave
a week's pay

When it is one measure of time (e.g., a day, one week), the apostrophe goes before the "s" (e.g., a day's pay, one week's vacation). When it is more than one measure of time (two days, five weeks), it goes after the "s" (e.g., two days' pay, five weeks' vacation).

apostrophes in time (temporal) expressions

Apostrophes in Time Expressions (Temporal Expressions)

Apostrophes are used in time expressions (e.g., three years' experience, two days' pay, one day's time). These are also known as "temporal expressions."

In a temporal expression, the apostrophe is positioned before the "s" for a single unit of time (e.g., a day) and after for plural unit of time (e.g., two days). For example:

I never did a day's work in my life. It was all fun. (Inventor Thomas A. Edison)
Alan was given two days' notice.
That is the equivalent of one year's pay.
My car came with three year's free insurance.

Imagine the Apostrophe Replaces "Of"

The following do not have any apostrophes in them:

I lived in Africa for 3 years.
She has six months left to run on her loan.

This point causes confusion among many. As a rule, you should only use an apostrophe in an expression where the word "of" might have been used. For example: