If my children stayed with me only on weekends, how do I translate that into months?

[Jimesa]

If your children stayed with you every weekend in 2016 from Friday night until Sunday then this would be 2 days times 52 weeks in the year which would equal 104 days. Then divide 104 days by 30 days (average days in a month) to get a total of about 3 1/2 months.