feat(dm): add first / last message date, dm duration and overall messages

src/lib/date.ts

@@ -0,0 +1,10 @@
+// https://stackoverflow.com/a/15289883
+export const getDistanceBetweenDatesInDays = (a: Date, b: Date) => {
+  const _MS_PER_DAY = 1000 * 60 * 60 * 24;
+
+  // Discard the time and time-zone information.
+  const utc1 = Date.UTC(a.getFullYear(), a.getMonth(), a.getDate());
+  const utc2 = Date.UTC(b.getFullYear(), b.getMonth(), b.getDate());
+
+  return Math.floor((utc2 - utc1) / _MS_PER_DAY);
+};