Note: this is not supposed to be useful to anyone besides myself. Have fun toying with it though.<br>
<br>
<input id=ar value=84><br>
<div id=out></div>
<script>
	var ar = document.getElementById("ar");
	var out = document.getElementById("out");
	
	ar.focus();
	
	function err(msg) {
		out.innerHTML = msg;
	}
	
	onpageshow = ar.onchange = ar.onkeyup = ar.onmouseup = ar.onblur = ar.onfocus = function() {
		if (ar.value == "")
			return err("");
		
		var html = "";
		
		var val = parseInt(ar.value);
		
		if (val.toString() != val) {
			return err("Invalid arrival time.");
		}
		if (val >= 24 && val < 100) {
			val *= 10;
			val += 5; // this does not make sense. It's just that all times I need are usually (x)x:x5 (e.g. 13:15)
		}
		
		if (val / 100 < 3 && val / 100 > 0.99) {
			val *= 10;
			val += 5;
		}
		
		if (val > 2400) {
			return err(">24h?");
		}
		
		if (val < 24) {
			html += "Interpreted as " + val + " 'o clock<br>";
			minute = 0;
			hour = val;
		}
		else {
			var minute = val.toString().substr(-2);
			if (minute >= 60) {
				return err("Wtf minute>=60?");
			}
			
			var hour = val.toString().replace(minute, '');
			if (hour == "") {
				return err("Zero hour."); // Yes. Yes this is a CnC reference.
			}
			
			hour = parseInt(hour);
			
			html += "Interpreted as " + hour + ":" + minute + "<br>";
		}
		
		var dep = {train : {}, bus: {}}; // departure times, by type of transport.
		var real_ar = {bus: {}, train: {}}; // real arrival time. When I'll be there as opposed to when I should be there.
		var overhead = {bus: {}, train: {}}; // should_arrive - actual_arrival (can be negative)
		
		dep.bus.hour = hour - 2;
		dep.bus.minute = 53;
		
		real_ar.bus.hour = dep.bus.hour + 2;
		real_ar.bus.minute = 16;
		real_ar.train.hour = hour;
		
		if (minute > 9 && minute < 40) {
			dep.train.hour = hour - 2;
			dep.train.minute = 59;
			real_ar.train.minute = 16;
		}
		else {
			dep.train.hour = hour - 1;
			dep.train.minute = 29;
			real_ar.train.minute = 46;
		}
		
		overhead.train = minute - real_ar.train.minute;
		overhead.bus = minute - real_ar.bus.minute;
		//if (overhead.bus < -15)
			//overhead.bus = -overhead.bus;
		
		html += "Depart at " + dep.train.hour + ":" + dep.train.minute + ", " + overhead.train + " minutes overhead<br>";
		html += "W " + dep.train.hour + ":" + (dep.train.minute == 29 ? "00" : "30");
		
		out.innerHTML = html;
	}
	
	setInterval(onpageshow, 150);
</script>