Unicorn and Lion

Alice came across a lion and a unicorn in a forest of forgetfulness. The lion lies every MOnday, Tuesday and Wednesday, and the other days he speaks the truth. The unicorn lies of Thursdays, Fidays and Saturdays, and the other days of the week he speaks the truth.

Lion: Yesterday I was lying.

Unicorn: So was I.

Which day did they say that?

 

Source: fitsbrain.com