Alice is walking throught the forest of forgetfulness. She wants to know what day of the week it is. She stops and asks a lion and a unicorn. Now the lion lies all of the time on Monday, Tuesday, and Wednesday. The unicorn always lies on Thursday, Friday and Saturday.

Alice asks the lion what day it is, he says, "Well yesterday was one of my lieing days." Well Alice cant figure it out just from the Lions answer so she asks the unicorn and the unicorn says, "Yesterday was also one of my lieing days."
What day is it?

Thursday

right
but would u pls elaborate?

From the days you listed the lion and unicorn lies on different days, the lion said "Well yesterday was one of my lieing days" and the unicorn said "Yesterday was also one of my lieing days." so one of them must be lying and the other is saying the truth.

since the unicorn said "also" it means that the lion was not lying so yesterday was the last day in the week that the lion lies at and today is the first day in the week that the unicorn starts lying, which is Thursday.