Here is the orginal danish article, translated (terribly) by google. The study had 7075 participants and was carried out by the Rockwool Foundation and The Danish Chamber of Commerce. Males aged 18-74 work on average 23 minutes more each day. If you only look at the time spent on an actual job, males work 3 hours and 49 minutes a day, while females work 2 hours and 28 minutes a day.

The article explains that there are several reasons for this: More females are emplyed in part-time jobs and more females are employed in the public sector, where the hours are fewer. Then it goes on to say that the average working time among males has dropped significantly from 5 hours and 54 minutes in 1964 to 3 hours and 49 minutes today. In 1964 males spent on average 29 minutes doing household chores, while that number today is 2 hours and 17 minutes.

I can't find the original report anywhere, but I will provide a link if it turns up.

Note that the low number of hours is because the study addresses each day of the year, not each working day of the year. And as you may know, Denmark has a lot of holidays.

Edit: Corrected a few spelling mistakes and so on.