Oh, Whitehouse.gov has an actual timeline.

https://www.whitehouse.gov/omb/briefing-room/2021/06/11/fact-sheet-department-of-defense-and-department-of-homeland-security-plans-for-border-wall-funds/

TLDR, day he became president, Jan 2021, He terminated wall funding he had legal control over, that's what I mentioned about the money going back to the DOD, called for Congress to reallocate cheeto wall funding, that request has been active for 3 years, and there's an official reiteration by the white house for Congress to cancel Cheeto wall funding.