I am going over some dates because im bad at remembering them but am struggling with the following.

If I say 先月会社を休みましたか。。。四日(よっか)休みました

Since ついたち、ふつか、みっか refer to day 1,2,3 etc. Im saying here "I am taking four days off this month" right?

What about if I want to say: "Im taking off the fourth of this month" how would this change? would I say よんび?