forgot your birthday

My husband forgot my birthday once, for a few hours at least. He made plans to have a whole day meeting on my birthday, He knows when my birthday is, I mean the date itself, but what he didn't realize that the date of the meeting was the date of my birthday. I was slightly hurt but I didn't make a big deal out of it, I probably would if the day of my birthday ended without him even remembering

I would demand for an explanation and will give him a second chance because I love him.