A phone call to the Eldest to wish her happy birthday goes something like this:
Me: Happy Birthday!
Her: Hmmm thanks, but it was yesterday.
Me: No, it's today. (Frantically looking at a calendar, because I don't want to be voted Worst. Mommy. Evah.)
Her: I know my birthday, you even wished me a good one on facebook.
Me: I did?
Me: Oh, I really wanted to make sure....
There is no way to recover from that. I wouldn't make a very good Temporal Witch (or Time Lord).