So I know in the OF, technically any of the Marian antiphons except the Regina Caeli are allowed for Night Prayer during the Triduum, but I like to use the one traditional for the time period when I can figure out what it is. But my 1962 Missal (which is what I usually use to make that determination) says that the Alma Redemptoris is used from Advent until the Purification, the Ave Regina is used from the Purification until tonight, the Regina Coeli is used from Easter until Trinity Sunday (although I stop that at Pentecost since I switch to my Ordinary Time breviary after Pentecost), and the Salve Regina is used after Trinity Sunday. It doesn't say anything about Holy Thursday or Good Friday (I think Mass substitutes for Night Prayer after the Vigil) ... which antiphon is most appropriate during the Triduum?

You can use Ave Regina for tonight (Maundy Thursday, which is same as Holy Thursday).

My guess is that the anthem is suppressed. I know it is suppressed at the end of Lauds during the Triduum. However if you had to say one it would be the Ave Regina Caelorum.

thanks, guys! Of course, now it's Easter! And that means I get to sing the Regina Caeli!!!!1