Thanks, that's the gap I care about most too. There's no magic number. I set the timeout comfortably above the slowest normal booking call, so a slow but healthy call never gets its claim released early. For a calendar API that usually means a few minutes rather than seconds. The important part is what the cleanup does when the timer fires: it checks the real calendar first and only releases the claim if no booking exists. A short timeout just means more checks. A long one holds the slot longer after a real crash.