Your licence
Atlas keeps its own clock. The licence term counts down inside your instance; Atlas does not call out to check. Reading and exporting your data is never gated by the licence — only Atlas's active work is.
A remittance advice buys a short courtesy period. A posted credit — funds actually received — extends the term. If a payment reported as sent has not arrived after three days, Atlas says so and gives notice before it stops working.
When a lease ends, Atlas locks first, and its own files are removed seven days later. Your data is yours and is never part of what is removed.