Hey thanks so much for the replies!
How dirty would it be to hold the reference to the clock actor in the game instance?
I was tweaking things last night and made an actor component so now the comms kind of look like this
Clock Sets TOD - On begin play casts to Game Instance and sets the Clock Actor reference as itself.
Time Component gets game instance and casts to Clock with its reference, then adds itself to Array of active components receiving time
When actor is changed or destroyed time component removes itself from the Clock array.