I was digging through some old stuff today and found this PHP function I wrote awhile back. You pass a time to the function along with a start time and end time, and it will determine if the time falls between that range. I figured I would post it on here in case anyone has a need for it.

function CheckTime($currentTime, $startTime, $endTime){
	// written 11/26/2006 by Patrick H. (patrickh@gmail.com)
	//
	// the time passed must meet all the below criteria to return 1 (true):
	//
	// - current hour needs to be equal or greater than start hour
	// - current hour needs to be equal or less than end hour
	// - current minute needs to be equal or greater than start minute (if current hour is ok)
	// - current minute needs to be equal or less than end minute (if current hour is ok)
	//
	// if any of those checks does not pass, it will return 0 (false)

	global $cHour;
	global $cMin;
	global $sHour;
	global $sMin;
	global $eHour;
	global $eMin;

	// break up current time
	$now = explode(":",$currentTime);
	$cHour = intval($now[0]);	// current time - hour
	$cMin = intval($now[1]);	// current time - minute

	// break up start time
	$start = explode(":",$startTime);
	$sHour = intval($start[0]);	// start of range - hour
	$sMin = intval($start[1]);	// start of range - minute

	// brek up end time
	$end = explode(":",$endTime);
	$eHour = intval($end[0]);	// end of range - hour
	$eMin = intval($end[1]);	// end of range - minute

	// this is the variable used to track the result of the checks
	$pass = true;

	if($sHour < $eHour){
		// the range is on the same day

		// compare to the start hour
		if($cHour < $sHour){
			$pass = false;
		};

		// compare to the end hour
		if($cHour > $eHour){
			$pass = false;
		};

		// compare to the start min
		if($cHour == $sHour){
			if($cMin < $sMin){
				$pass = false;
			};
		};

		// compare to the end min
		if($cHour == $eHour){
			if($cMin > $eMin){
				$pass = false;
			};
		};

	} else {
		// the range is overnight, so the logic is a little different

		if( ($cHour < $sHour) && ($cHour > $eHour) ){
			$pass = false;
		};

		// compare to the start min
		if($cHour == $sHour){
			if($cMin < $sMin){
				$pass = false;
			};
		};

		// compare to the end min
		if($cHour == $eHour){
			if($cMin > $eMin){
				$pass = false;
			};
		};

	};

	// done with check, return the result
	if($pass == false){
		return 0;	// failed
	} else {
		return 1;	// passed
	};

};

// test it out
// make sure you use military time
// usage: current time, range start time, range end time

echo CheckTime("06:30","15:20","06:45");	// this should return 1