refactor: format and lint codebase (#971)

app/assets/javascripts/Utils/CalculateDifferenceBetweenDatesInDays.ts

@@ -0,0 +1,19 @@
+import { MILLISECONDS_IN_A_DAY } from '@/Constants'
+
+export const calculateDifferenceBetweenDatesInDays = (firstDate: Date, secondDate: Date) => {
+  const firstDateAsUTCMilliseconds = Date.UTC(
+    firstDate.getFullYear(),
+    firstDate.getMonth(),
+    firstDate.getDate(),
+  )
+
+  const secondDateAsUTCMilliseconds = Date.UTC(
+    secondDate.getFullYear(),
+    secondDate.getMonth(),
+    secondDate.getDate(),
+  )
+
+  return Math.round(
+    (firstDateAsUTCMilliseconds - secondDateAsUTCMilliseconds) / MILLISECONDS_IN_A_DAY,
+  )
+}