OK so spent a little more time and sussed that if I press both function buttons together and then push the H (hour)
recessed button on the back it advances the date. YEA
But if I swap to the M (minute) recessed button it puts the screen back to the time screen and advances the minutes.
Even with both function buttons still pressed
Funny that the H which in time setting alters the left two digits/hour (1-12) but in date/month setting it does the right two.
And I still haven't found the way to set the Month.