First I'd like to say welcome to another person from pipetown.
Here is the page your looking for:
http://www.state.il.us/agency/idol/faq/qamwot.htm "You are entitled to pay at time and one half your regular rate of pay if you worked over 40 hours in a workweek. You will need to ask your employer for their definition of a workweek."
"Does my employer have to pay me time and one half or double time for working a legal holiday or a Sunday?
No. If working the legal holiday or Sunday puts you over 40 hours in a workweek, then your employer must pay you at time and one half of your regular rate of pay for those hours over 40. However, if your employer’s policy allows for payment of time and one half or double time, then the employer must honor the agreement."
I remember working for places in the past that did not count holidays, vacation, sick, or training twords your work week hours. I thought it was a way to cut my pay check.
You should make a decision and keep it as part of your policy along with how many paid days off, which ones, and what if the holiday is on a Sunday.
Tom