You don’t have to write code for calculation of the “cheap hours”, of course you have to write code to start your devices in those cheap hours.
The aWATTar-Binding already lets you create specific Things for specific devices. As in my example above, you configure a device by telling the thing to search for the cheapest price for xx hours. If you know, your dishwasher needs 2h or your EV loads in 6h typically, you just tell the “BestPrice”-Thing how long the device needs power and if it has to be consecutive hours and from what hour of the day it should start searching, then you get ab bunch of pre-filled items, you can work with:
so, basically you can just use the first one, which tells you: “Now is the cheapest hours”, but you can also use the DateTime-items or even the “Countdown”-items to prepare. The second to last here tells you, that for potentially loading my Kia EV6 the best hours (yesterday) would start at 23:00 and last till 03:00. The items get filled daily at around 13h, that’s the time, the EPEX spot prices are published. So best is to start searching for cheap hours at around 14h/15h (CET that ist).
So, I’d be happy, if the Tibber-Binding would also provide that same logic, as I find it quite cool and saves a lot of rule-work yourself.