separaded endpoints + cleaned page templates + added constants to time formatting

Backend/static/script.js

@@ -79,3 +79,9 @@ function navigateWeek(element, event, direction) {
 function logoutUser() {
   fetch("/user/logout", {}).then(() => globalThis.location.reload());
 }
+
+function checkAll(pattern, state) {
+  for (let input of document.querySelectorAll(`input[id^=${pattern}]`)) {
+    input.checked = state;
+  }
+}