LTD beat me to it, lol.
My first thought was ................... well it's a Saturday, you and the DD's could go away on a nice all day jaunt (a surprise for them, do not tell ahead of time), maybe to a zoo, or a water park, or something, and then maybe a picnic in a park in another town, lol
You get the idea.
Your birthday, your plans.
If it were me, I would NOT contact him. I would just be prepared to spend my birthday my way with my lovely daughters.
J M H O
Love and hugs,