Notice for 15th YR / 18e: You have until the 8th of March to arrange your match inside your 14 day window, otherwise we will have to enforce rule 4.5:
4.5 If both regiment contacts cannot agree on a match time/date, then the second Sunday at 7:00pm UK Time will be set as default.
As it stands, the second Sunday from the challenge is Sunday the 11th of March.