Yes. You switch of everything, including the pump, on a time clock...

Only if you want to break the law (on a recently installed system)

Part L1

1.41 Gas and oil fired hot water central heating
system controls should switch the boiler off
when no heat is required whether control is by
room thermostats or by thermostatic radiator
valves:

a) The boiler in systems controlled by
thermostats should operate only when a space
heating or vessel thermostat is calling for heat.

b) Where it is proposed to effect control by
thermostatic radiator valves, a room thermostat
(or other device such as a flow switch) should
also be provided to switch off the boiler when
there is no demand for heating or hot water.

Christian.