Sames prices, whatever time of year IF I AM SCHEDULED TO WORK THAT DAY.
However...... if I'm choosing to take the day as a vacation day, and not booking anyone else.. I have recently decided that if someone nags me enough or is desperate enough to have me on my 'day off'... then there WILL be a surcharge.
Think of it as overtime pay. In other areas of business, when staff works over 40hrs, they get time & a half or double time.
So, it seems fair to me.
I have not determined what yet.
When I have, I will post it on my price list.