According to Pew, men spend an extra 4 hours per week supporting their families compared to women.

https://www.pewresearch.org/fact-tank/2019/06/12/fathers-day-facts/ft_18-05-01_fathersday_time/

Over 18 years, that adds up to 3,744 hours, or 156 days.

Note that as children get older, they take less time to take care of, and the pew study appears to look at younger children. Which means the gap might actually be larger.

Without children in the picture, there is a deficit of 10 hours per week, which adds up to 22 days per year of free time lost to men.

The only reason women even come remotely close to men in terms of time and effort is because they spend more time on child care compared to men. Take that out of the picture, and women are basically swimming in free time compared to men.

Note that this isn't the only study that shows this trend. Some more data points can be found here:

VerBruggen, R. (2019, June 11). The Myth of the 'Lazy' father. Institute for Family Studies. Retrieved October 21, 2019, from https://ifstudies.org/blog/the-myth-of-the-lazy-father

And here:

Time spent in paid and unpaid work, by sex https://stats.oecd.org/index.aspx?queryid=54757 oecd

The gap closes when women work full time but it is still 1 hour per week in favor of women even when both spouses hold down full time jobs. Which means men across the board are doing more to support their families than women are.

Why is this important?

Well, I commonly see people claiming exactly the opposite of this. I don't think it's fair that men are derided as being lazy or not doing enough when the data shows exactly the opposite of this. The time and effort that men put into their families is simply not respected the same way we respect a woman's contributions. We care about the fact that a mom plays with her kids, but not the fact that the father performed less desirable work, both on the job, and at home, to provide everything that was necessary for that to happen.