Quick question, if my 90 days non-B visa is set to expire on April the 24th, when is the latest I (my school) can apply for a 1 year extension?
TLDR : Answer Summary
To extend your 90-day Non-B visa, you should apply at the latest by April 24th, which is the expiration date. However, it's advisable to apply at least 30 days prior to ensure you have enough time to acquire any necessary paperwork.