Q. Kevodo, Are we allowed to celebrate birthday in “bein hametzarim” (vacation) at home with no music and just family?
A. It is permitted to celebrate a birthday party during the Three Weeks until Rosh Chodesh Av. (Laws of Daily Living: The Three Weeks (p. 45) .
Rabbi A. Bartfeld as revised by Horav Y. Hirshman, Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu, Horav Kalman Ochs, and Horav Dovid Bartfeld consulting in need Horav Hagaon Rav Yitzchak Berkowitz Shlit’a