if引导的时间状语从句例句

if当“如果”讲引导的叫条件状语从句；如果当“是否”讲引导的叫名词性从句，不可能引导时间状语从句呀？
eg: If it rains tomorrow,we won't go there.

If you have a cold,you will feel very bad.

I’ll come when if I’m free