The 635 Hatfield to Watford service has been added to the wide-ranging slate of changes for buses in the area from August 30. This month was already set to see a significant reorganisation of Hertfordshire buses. 635 bus route (Image: Intalink)Operator Uno said: “We have tried to plan the times at the General Hospital in Watford around the shift changes. The first bus toward Watford will now depart at 6am while the first bus towards Hatfield Business Park will depart at 7.45am. The final departure from Hatfield will leave at 6.30pm and the last bus from Watford General Hospital will depart at 7.50pm.