i am leaving from new York to Israel on dec. 21 at 6:00 p.m. IY”H. it is asarah b;teves. when do I begin the fast. Thank you.
The fast starts for you when it is Alos Hashachar [daybreak] where you are at the time. In your case this will about seven hours in to the flight. See Chaitables.com and enter your flight info for exact details.