"Had a client ask me why I closed at 5pm on the last day of tax season"

I would have told them, good point.  Next year we are closing at 5pm on April 14th.  

The problem these days is the fact that you can't escape clients.  If you ever make the mistake of returning a phone call with a cell phone, they lock that number into their phone and now they think you are available 24/7 for all of their life threatening tax emergencies.