I propose to add a sensor block that emits a redstone signal with strength depending on the type of event. For example strength of redstone signal could be:
0 - of no events
3 - of blue moon(this event will be added?)
7 - on harvest moon
15 - on blood moon

This sensor can be useful for various redstone mechanisms, ex. for alarm system of blood moon.

Like a Lunar calandar?

I may add something for events but the sensor will let you choose what event powers the sensor

Well, I mean just something that let you to react for event like blood moon with a redstone signal.
Of course you can add a few sensor, for separate event each, as you wish or something.

For example place a blood moon sensor, connect with redstone dust to a alarm block(or something) and/or mechanism that open/close a gates. If blood moon will occur, then loud siren of alarm will be hear and gates will close.
Such a sensor can have many other uses. :)