I've done tea parties for friends. I give party favors - last year it was home-made Chai Tea in clear bags w/ recipe tied w/ ribbon at top of bag. I place the favors in a large basket & remind guests to take one as they leave. I like to greet them @ door as they arrive, & be at door as they leave as well, so often hand favor to them at that time.
Sounds like it will be a nice gesture, with or without date on the bag.