In case anyone wants to look at a specific binding the API is here:
Might be OH4 specific, but hopefully it helps someone else. The start of the rateChange rule needs to be changed to the following.
The old code line no longer worked, and caused the hour variable on the following line to be set to the first 2 digits of the year, 2024 = 20
val String dateString = String::format( "%1$tH:%1$tM", new java.util.Date ) //get current hour as a string