Have read a bunch of 90 day report, reports. But can't find the one thing I need; how many days before your 90 days is up can you go in and report, or do you have to do it on the 90th day. Thankyou.
TLDR : Answer Summary
You can report your 90-day stay 15 days before it expires and up to 7 days after. Some users have mentioned that immigration may count the days differently, where 15 days before actually refers to 14 days if using a common counting method. Reporting can be done in person, online, or by postal mail.