code: public static CronSchedule weeklyOnDayAndHourAndMinute(int hour, int minute, Integer... daysOfWeek) {
          if (daysOfWeek == null || daysOfWeek.length == 0) {
              throw new IllegalArgumentException("You must specify at least one day of week.");
          }
  
          String expression = String.format("0 %d %d ? * %d", minute, hour, daysOfWeek[0]);
          for (int i = 1; i < daysOfWeek.length; i++) {
              expression = expression + "," + daysOfWeek[i];
          }
  
          return of(expression);
      }
docs: Creates cron expression which schedule task execution
  every given days of the week at the given time.
  Use Calendar object constants to define day.
  
  @param hour of schedule
  @param minute of schedule
  @param daysOfWeek - Calendar object constants
  @return object