And, they said, the ideal amount of work per week was different for men and women, who typically spent more time on domestic duties.
Women were best off working just 34 hours a week "to take into account the amount of caring work women do at home", they said.
The researchers noted that the International Labour Organisation's standard work week limit of 48 hours, set 80 years ago, was based on a labour market in which most paid jobs were worked by men - many of them with wives at home taking care of the housework.
"Almost half of the workforce is [now] made up of women and two-fifths of employed adults hold down a job while caring for children or elderly parents," they said.
"Women are still working in a labour market that systematically disadvantages them in terms of pay, conditions and rewards ... They usually spend more time caregiving and have very different experiences on the job, because they have lower pay - earning 17 per cent or $277.70 less per week on average, full time - along with less paid leave entitlement."
On that note, ladies, we suggest you take an early mark.