it was several months ( )i was able to have a day off to vis

it was several months (before)i was able to have a day off to visit my parents.意思是"几个月后我才能休息一天去看望父母.",直译是"在我能休息一天去看望父母之前要有几个月".如果用that引导定语从句,意思就不对了,语法也不对.