Make the Thrimbletrimmer clock use Wubloader's bus time start setting

thrimbletrimmer/clock.html

@@ -13,14 +13,14 @@
 		<div id="clock"></div>
 		<div><input type="number" id="delay" value="10" min="0" /> seconds of delay</div>
 		<script type="text/javascript">
-			const BUS_START_TIME = 1605290400;
+			let busStartTime = null;
 
-			let updateClock = () => {
+			function updateClock() {
 				let delay = parseInt(document.getElementById("delay").value);
 				if (isNaN(delay)) {
 					delay = 0;
 				}
-				let time = new Date().getTime() / 1000 - delay - BUS_START_TIME;
+				let time = (new Date() - busStartTime) / 1000 - delay;
 
 				let sign = "";
 				if (time < 0) {
@@ -40,9 +40,17 @@
 				}
 				let formatted = sign + hours + ":" + mins + ":" + secs;
 				document.getElementById("clock").innerText = formatted;
-			};
+			}
+
+			async function initialize() {
+				const dataResponse = await fetch("/thrimshim/defaults");
+				const data = await dataResponse.json();
+				busStartTime = new Date(data.bustime_start);
+
+				setInterval(updateClock, 1000);
+			}
 
-			setInterval(updateClock, 1000);
+			initialize();
 		</script>
 	</body>
 </html>