revert(api): decouple api from curriculum

This reverts commit c077ffe4b9
via PR #40703

api-server/server/utils/date-utils.js

@@ -0,0 +1,18 @@
+import moment from 'moment-timezone';
+
+// day count between two epochs (inclusive)
+export function dayCount([head, tail], timezone = 'UTC') {
+  return Math.ceil(
+    moment(
+      moment(head)
+        .tz(timezone)
+        .endOf('day')
+    ).diff(
+      moment(tail)
+        .tz(timezone)
+        .startOf('day'),
+      'days',
+      true
+    )
+  );
+}