Hawkhurst Bus Station eventually closed in February 2008 (allowing the event to be covered by the Invicta Newsgroup, which had been launched about 18 months earlier), and this view of all-Leyland PD2 DH399 could be around 40 years earlier. There's just a small possibility that this picture dates from earlier than 1968 when it was, at least theoretically, renumbered to 5399, as it appears to be still carrying its DH-prefix fleet number, but personally I'm too young to have been an active enthusiast until after the last of them were withdrawn in 1970 so can't recall from personal experience whether M&D bothered to apply the new numbers to the survivors from this batch of vehicles.
So it's a little uncertain exactly what date this picture was taken. Allocation records show DH399 was moved from HK (Hawkhurst) to M (Maidstone) in March 1967, and stayed at the latter until withdrawal, but as the picture shows it on the 5 (on which both HK and M operated, as did Hastings) it might imply that the picture was from before the 5 went OMO in September 1968.
Derek J