T.T.
I was friends with someone for 8 years. 6 of the 8 years I celebrated it on the wrong day (22 instead of the 20th).
She never mentioned it to me EVER. I found out I was celebrating the wrong day from her husband.
She said as long as I remembered she was ok...and she got to celebrate it TWICE. :)
Bottom line, she should remember, no excuse. I too am old fashioned about such things.
Sending good thoughts and birthday wishes to you. :)