My 7 month old son's father who pays child support says that legally at one year he is entitled to have baby for 30 consecutive days. Is this true? He goes 3 weeks at a time without seeing child and doesn't know him at all. I have not signed anything yet he is having papers drawn up now.

It would be true ONLY if there is a court ordered custody/visitation agreement that specifies that.

I assume you were never married (or no longer married; which?). But that he is the legal father (either listed on the birth certificate or signed an acknowledgment of paternity or was designated by the court that issued the support order.

If there is no custody/visitation order, then you have equal rights to the child. However, since he was ordered to pay support then there is probably something official designating you as primary custodial parent. So without a formal visitation agreement, you are in control.

But he can go to court to establish a visitation schedule.

He is entitled to visitation and he will be entitled to take the child to his home for over night visits. Normally if he lives in the area, he may have joint custody, you have child one week and he has child one week.
Or he may get the child every other weekend and a day during the week.

Only if he lives a long distant away, perhaps another state does he get the child for a full month ( expect perhaps summer visits)

But you need first if you do not have it a custody order and then a visitation order.

If he visits with the child every three weeks, that is visiting and he would know the child.