From this page, I see this sentence:
Note: Be careful of the tense of the verb that comes before 「前」 and 「後」. 「前」 is non-past while 「後」 is always past tense.
I am confused because it is quite weird to disallow the usage of non-past tense before 後. What if I'm talking about the things that I will do tomorrow? For example, which should I use if I want to say "I will go to school after I have breakfast tomorrow"?