Danuin

A child of time, Danuin represents Day in the book Lost Tales. He has two brothers named Ranuin and Fanuin, and their father is Aluin. Not sure if ICE/MERP did anything with these individuals or if they made them into Maia--but if they did so, then Danuin, Fanuin, and Ranuin would not only be Maia, but they would be Maiarindi as well. They appeared in the guises of old men, similar to the Istari look, and Danuin is considered the first son being Day, and followed by Month and Year, and appears as a small/short man. Danuin also had short hair and a small beard.

MERPS/ICE
It is unknown if MERP actually used these characters, but given that they are Ainur who exist in Arda--GM's may use them in their campaigns if they want to. Obviously GMs will have to come up with stats and levels for them using the ICE character law.