Gazelle/classes/class_time.php

<?
if (!extension_loaded('date')) {
	error('Date extension not loaded.');
}

function time_ago($TimeStamp) {
	if(!is_number($TimeStamp)) { // Assume that $TimeStamp is SQL timestamp
		if($TimeStamp == '0000-00-00 00:00:00') { return false; }
		$TimeStamp = strtotime($TimeStamp);
	}
	if($TimeStamp == 0) { return false; }
	return time()-$TimeStamp;
}

function time_diff($TimeStamp, $Levels=2, $Span=true, $Lowercase=false) {
	/*
	Returns a <span> by default but can optionally return the raw time
	difference in text (e.g. "16 hours and 28 minutes", "1 day, 18 hours").
	*/
	if(!is_number($TimeStamp)) { // Assume that $TimeStamp is SQL timestamp
		if($TimeStamp == '0000-00-00 00:00:00') { return 'Never'; }
		$TimeStamp = strtotime($TimeStamp);
	}
	if($TimeStamp == 0) { return 'Never'; }
	$Time = time()-$TimeStamp;
	
	// If the time is negative, then it expires in the future.
	if($Time < 0) {
		$Time = -$Time;
		$HideAgo = true;
	}

	$Years=floor($Time/31556926); // seconds in one year
	$Remain = $Time - $Years*31556926;

	$Months = floor($Remain/2629744); // seconds in one month
	$Remain = $Remain - $Months*2629744;

	$Weeks = floor($Remain/604800); // seconds in one week
	$Remain = $Remain - $Weeks*604800;

	$Days = floor($Remain/86400); // seconds in one day
	$Remain = $Remain - $Days*86400;

	$Hours=floor($Remain/3600); // seconds in one hour
	$Remain = $Remain - $Hours*3600;

	$Minutes=floor($Remain/60); // seconds in one minute
	$Remain = $Remain - $Minutes*60;

	$Seconds=$Remain;

	$Return = '';

	if ($Years>0 && $Levels>0) {
		if ($Years>1) {
			$Return .= $Years.' years';
		} else {
			$Return .= $Years.' year';
		}
		$Levels--;
	}

	if ($Months>0 && $Levels>0) {
		if ($Return!='') {
			$Return.=', ';
		}
		if ($Months>1) {
			$Return.=$Months.' months';
		} else {
			$Return.=$Months.' month';
		}
		$Levels--;
	}

	if ($Weeks>0 && $Levels>0) {
		if ($Return!="") {
			$Return.=', ';
		}
		if ($Weeks>1) { 
			$Return.=$Weeks.' weeks';
		} else {
			$Return.=$Weeks.' week';
		}
		$Levels--;
	}

	if ($Days>0 && $Levels>0) {
		if ($Return!='') {
			$Return.=', ';
		}
		if ($Days>1) {
			$Return.=$Days.' days';
		} else {
			$Return.=$Days.' day';
		}
		$Levels--;
	}

	if ($Hours>0 && $Levels>0) {
		if ($Return!='') {
			$Return.=', ';
		}
		if ($Hours>1) {
			$Return.=$Hours.' hours';
		} else {
			$Return.=$Hours.' hour';
		}
		$Levels--;
	}

	if ($Minutes>0 && $Levels>0) {
		if ($Return!='') {
			$Return.=' and ';
		}
		if ($Minutes>1) {
			$Return.=$Minutes.' mins';
		} else {
			$Return.=$Minutes.' min';
		}
		$Levels--;
	}
	
	if($Return == '') {
		$Return = 'Just now';
	} elseif (!isset($HideAgo)) {
		$Return .= ' ago';
	}

	if ($Lowercase) {
		$Return = strtolower($Return);
	}
	
	if ($Span) {
		return '<span class="time" title="'.date('M d Y, H:i', $TimeStamp).'">'.$Return.'</span>';
	} else {
		return $Return;
	}
}

/* SQL utility functions */

function time_plus($Offset) {
	return date('Y-m-d H:i:s', time()+$Offset);
}

function time_minus($Offset, $Fuzzy = false) {
	if($Fuzzy) {
		return date('Y-m-d 00:00:00', time()-$Offset);
	} else {
		return date('Y-m-d H:i:s', time()-$Offset);
	}
}

function sqltime($timestamp = false) {
	if ($timestamp === false) {
		$timestamp = time();
	}
	return date('Y-m-d H:i:s', $timestamp);
}

function validDate($DateString) {
	$DateTime = explode(" ", $DateString);
	if(count($DateTime) != 2) return false;
	list($Date, $Time) = $DateTime;
	$SplitTime = explode(":", $Time);
	if(count($SplitTime) != 3) return false;
	list($H, $M, $S) = $SplitTime;
	if($H != 0 && !(is_number($H) && $H < 24 && $H >= 0)) return false;
	if($M != 0 && !(is_number($M) && $M < 60 && $M >= 0)) return false;
	if($S != 0 && !(is_number($S) && $S < 60 && $S >= 0)) return false;
	$SplitDate = explode("-", $Date);
	if(count($SplitDate) != 3) return false;
	list($Y, $M, $D) = $SplitDate;
	return checkDate($M, $D, $Y);
}
?>