I am currently a student abroad and yom kipur falls on a day that we are doing a school trip I really want to attend. Would it be okay if I start my fast before (like if I was in a different time zone) to still have my hours of fasting but I just do them beforehand so I can still attend the trip?
My apologies, but I didn’t see your question until after Yom Kippur, and at this point the question is no longer applicable. Yom Kippur is from sunset on Yom Kippur, until nightfall the next day. It goes according to the Jewish calander day. it is not as if we can choose our own hours. I do respect the fact that you did ask the question, I bless you that G-d grant you a good year.