Update table display on board page, in preparation for offering different 'table' styles.

src/lib/utils/time.ts

@@ -102,3 +102,27 @@ export function calculateDelay(loc: DelayInput): {
 		return { val: `${absDiff}E`, type: 'early' };
 	}
 }
+
+/**
+ * Accepts a pair of times (string or Date) and outputs a delay class 'delay-early', 'delay-late' or 'delay-rt'
+ * @param sched Scheduled Time (string, Date)
+ * @param act Actual Time (string, Date)
+ */
+export function delayClassFromTimePair(sched: any, act: any): string {
+    if (!sched || !act) return '';
+
+    const s = new Date(sched).getTime();
+    const a = new Date(act).getTime();
+
+    if (isNaN(s) || isNaN(a)) return '';
+
+    const diff = a - s;
+    const oneMinute = 60000;
+
+    // on-time if within one minute
+    if (Math.abs(diff) < oneMinute) {
+        return 'delay-rt';
+    }
+
+    return diff > 0 ? 'delay-late' : 'delay-early';
+}