The official answer is that Prime Day 2022 ends at 11.59pm on Wednesday July 13. But the more complicated answer is that it depends on your time zone. In the US, Amazon Prime Day ends at 11.59pm PDT Wednesday July 13, but that's actually 2.59am EDT Thursday July 14.
In the UK it's a more straightforward cut off at 11.59pm BST Wednesday July 13.
But that's all for Amazon's own specific deals, and we would expect to see deals from the likes of Newegg and Best Buy hanging around just that little bit longer.