code: public Date getExecutionTimeNext() {
  
          if (!m_active || (m_trigger == null)) {
              // if the job is not active, no time can be calculated
              return null;
          }
          if (m_nextFireTime == null) {
              // in case next time is not set, check if the trigger supplies a valid next fire time
              Date next = m_trigger.getNextFireTime();
              if (System.currentTimeMillis() < next.getTime()) {
                  m_nextFireTime = next;
              }
          }
          return m_nextFireTime;
      }
docs: Returns the next time at which this job will be executed.<p>
  
  If the job will not execute again, <code>null</code> will be returned.<p>
  
  @return the next time at which this job will be executed