Question: During the game, can I call a tile to expose a year hand such as 2023 or a NEWS?

Answer: A player may not call to expose a group of single tiles unless the tile called is the winning tile that gives them Mah Jongg.  This rule also applies to pairs. A single tile is defined is a stand-alone tile or a group of tiles that are not identical i.e. 2023 or NEWS.

Source:  Mah Jongg Made Easy, page 23, para. 10