docs: private static long daysBetween(Date date1, Date date2) {
          long diff;
          if (date2.after(date1)) {
              diff = date2.getTime() - date1.getTime();
          } else {
              diff = date1.getTime() - date2.getTime();
          }
          return diff / (24 * 60 * 60 * 1000);
      }