Once apon a time Apollo, Aries, Hades, and Hephaestus were best friends friends, and used to hang out together every day.
HOW DARE YOU!
Until one day Hades went into the underworld for long periods of time
Hades's actions made Apollo, Aries, and Hephaestus furious, so they went to Zeus, Hades's brother and told him about what happened.
Im sorry I have made a grave mistake...
We forgive you as long as you dont ALWAYS go in the underworld
So Zeus goes to Hades's palace and Hades gets very angry because he said he has work to do.
Hades was enraged by Zeus telling him to get out of the underworld so they started a war against each other.
During the war Hephaestus uses his blue fire whirl to wipe out his army, after this Hades realizes he was acting irrationally and he can never win so he went to apologize to his friends and made a schedule so he would be in both places for equal amount times.