How to approach W about OM

[OfficerInNeed]

My W and I are schedule to go a concert 03/23 as mentioned in a previous post it will be a 3-4hr drive. My wife does plan on going to work the morning of. What I did and have yet told her is the morning of I scheduled for her to go for a spa treatment that I think she could really benefit from. She has work leading up to and including the day we are going...I wanted to do this before we go so I decided the day of.

Now the question is how do I tell her and how in the world do I convince her to not go to work or leave early? I thought about just asking her to take off for such reason or writing a little note...I think I got myself in a little jam but I am hoping somehow it can work out.