In your case, you are the noncustodial parent. The children do not live with you, they visit every other weekend. I'm not sure what you read, however the total number of days for the year, if they stayed with you for two days every other weekend would be 52 days (26 weeks x 2 days per week). This would indicate that they stayed with you almost two months. This is what you should enter for the number of months living with you.
There can be only one custodial parent unless you live together with the children and the other parent. The custodial parent, can sign a waiver for you so there's no confusion about claiming them. You can print the form by using the link here:
