You cannot find it using catchup-by-day but it is there on the A-Z selection. However, if you want to watch the version originally broadcast on the 14th you have to select the one apparently shown on the 15th, etc.
So I have a SL set up for this and for whatever reason the recording just stopped less than 10 mins in no reason. I was in the house so no reboot or I would know and it just stops. This was Friday night 9pm programme. So this meant I had to go to Catch Up. I went through the guide to the showing and it says watch from catch up. It started playing however it is the nights before. I tried searching through the Catch Up options and Friday nights shows were not there at all so they are getting wrongly indexed or something.
So 2 issues here. My brand new V6 failed a recording part way through for no reason and then the subsequent catch up as a backup is not there either..... It is 24 hours later so no reason why it shouldn't be.