From the “Future Echoes” episode of Red Dwarf:
RIMMER: Lister, it *has* happened. You can’t change it, any more than
you can change what you had for breakfast yesterday.
LISTER: Hey, it hasn’t happened, has it? It has “will have going to have
happened” happened, but it hasn’t actually “happened” happened yet,
RIMMER: Poppycock! It will be happened; it shall be going to be
happening; it will be was an event that could will have been taken
place in the future. Simple as that. Your bucket’s been kicked, baby.
Now then: Science hopes to change events that have already occurred.