My son is 6 , his father is not in the picture at all. My son's grandparents on his father side took me to court this past year in Jan. We agreed in the stipulation that they would come visit my son every other month. It's been 4 months and I have received no e-mails,calls or visits from them. It's confusing to my son to have the grandparents pop in and out when they feel like it. How long do grandparents have rights? Until the child's 18?

They potentially could have rights until the child is 18. Of course, these kinds of orders are modifiable. So, if it's not working out, go back and ask for a modification.

Grandparents don't usually get a lot of time in California (nothing like shared custody orders between parents) so I'm not surprised by the every-other-month visitation schedule. If you want to study the law on the subject, take a look at Family Code Sections 3102-3104 (3104 being the main one people rely on).

3104 says that upon a showing that there has been a change of circumstances justifying a modification (such as that there is no longer a bond between the child and the grandparents) a parent may move to terminate the order and, if shown, the court must grant the termination.