Short trip to Dubrovnik

Hi has anyone taken a short trip (4 days) to Dubrovnik? We fly out on a Thursday and fly back to Uk on a Sunday. I am trying to work out whether LFT taken on the Thursday in the Uk before we fly will be valid for our entry into the UK on the Sunday. Government website states if you fly on a Friday a test taken on a Thursday, Wednesday or Tuesday is valid but also refers to within 72 hours. Has anyone done this?