This smells of an XY Problem. If I understand you have a number of scenes that need to be triggered at a specific time. You want to write a rule that runs every minute and checks to see if it’s time to run a given scene.
In general, polling is not the best way to achieve anything. It would probably be better to use Timers.
However, in this specific use case, have you seen Creating Capabilities with Rule Templates: Time of Day ? There are rule templates that you can use to drive your time based scenes and you don’t even have to code anything to handle the timing, just set some DateTime Items.
If you have more complex needs (e.g. different times for different types of days) see Time Based State Machine [3.2.0;3.4.9] . Again, all you need are some specially configured DateTime Items.
In answer to your question though, I don’t think time comparison blocks have been implemented yet.