Viewers of this Wednesday's CNN presidential debate in Arizona could see the candidates' faith on display quite literally.

That's because the debate takes place on Ash Wednesday, the first day of the Catholic holy season of Lent.

View Photo Gallery: Going into February with four contests behind them, the four remaining presidential contenders continue on the campaign trail.

Catholics typically observe the holy day by attending mass and receiving ashes, which they wear on their foreheads until the end of the day.

Both former House speaker Newt Gingrich (R-Ga.) and former senator Rick Santorum (R-Pa.) are Catholic. Spokesmen for both candidates did not immediately respond to a request for comment Monday morning.