If I understand correctly, I must leave the U.S. BEFORE the date stamped in my passport (or on the I-94 form) by the immigration officer upon entry.
What’s the minimum amount of time I should wait between two stays?
If I land in Washington (USA), travel to Halifax (Canada), stay in Canada until Calgary (Canada), visit Alaska (USA) for 2 months, and then re-enter the U.S. a few weeks later via Canada—how are "stays" and days counted?
I can’t find any official documents explaining how this counting works. From what I’ve heard from recent travelers, practices have changed in recent years. Is the counting left to the discretion of the immigration officer, or is there something less arbitrary I can rely on?
Thanks to anyone who can answer this question.










