Yes – a DAY TC is definitely available (paper ticket, to be discontinued in Jan 23) but I fear I’m looking in vain for a DAY TC on any type of Smartcard. I really want to avoid a paper ticket because of the need to pass quickly thorough barriers. I think it remains the best option to either put up with a paper DAY TC or get a WEEKLY one on Oyster (or one of the other Smartcards), possibly surrendering it after the Challenge.
If anyone can report on actual experience of buying a DAY TC for Z1-9 on a SmartCard then please report!