Need help with if..then value range

I have a flash/PHP clock I am building, but a part of it is driving me nuts.

I want a simple if…then that basically says this:

If it is Thursday, between the hours of 10:20am and 12:30PM, show this. If not, then show this.

Here is how I’ve got it so far:
if (weekDay==“Thursday” && (hour >= 10 && minutes >= 20 && myAMPM==PM) && (hour == 12 && minutes <=30) ){
thisOn.is._visible=true;
} else{
thisOn.is._visible=false;
}

but it is not correct. I just can’t get my head around how to actually write it. I basically need to know how to “group” value sets for comparison, I believe.

The “hours” are pulled from a PHP file, and are in 24-hour format.

How can I write it properly?

Thanks
Bryan