Google calendar is ridiculous. Can't move an event.
So, in my Google calendar, out-of-the-box each email looks to be assigned 4 calendars: my name, Birthdays, Family, Tasks. These are stock and can't be renamed or removed.
I have my friends and family's birthdays, and you wanna guess which calendar its in? I'll give you a hint, its not "Birthdays", its in my name. Ok, fine, I'll just move them.... nope. I can copy it to Family, that's it. Birthday calendar, at this point I might as well just delete it since it doesn't have any birthdays in it.
Sure... I could remake all of them manually, but there has to be an easier way, right?