No query by expiry dates can be performed on virtually any whois server, let alone the UK whois server.
There is no hard-and-fast timetable for drops on the UK system. Domains become 'DETAGGED' which is roughly the equivalent of ON HOLD when they haven't been renewed. But they can be DETAGGED for years. Some domains from 1997 that weren't renewed are still DETAGGED. Nominet has to write to each and every domain holder, asking if they want to keep the domain. If they don't get a response within a couple of months, then the domain becomes SUSPENDED, which is equivalent of DELETING. However, SUSPENDED domains don't get deleted for a minimum of 21 days, and even then sometimes they don't become available for several months.