Smart TRVs and non smart boiler

I received some Sonoff Smart TRVs yesterday and paired them directly with ZHA. The dashboard is really nice.

Each TRV reports the current temperature, target temperature and whether it is idle or heating. My non smart boiler has a timer so the heating only works on a schedule.

In the chart you can see the radiator is logged as heating since yesterday, however the boiler is currently only heating when I switch it on - currently once per day in the evening.

How do I add a schedule to HA so that the TRVs do not show heating when there is no heat being generated?