Do Catholics have a moral obligation to pray twice a day?

[Plato03]

I am a lay Catholic. I was told by a priest in confession that the failure to do morning and evening prayer is a mortal sin. I was taken aback because I had never heard such a thing. It was my understanding that this is good practice and should be encouraged, but is it a mortal sin if one does not?

 

[Michelle_Arnold]

I’ve never heard of such a thing either. The priest should be asked to provide relevant citations from authoritative Church documents.