code: public Date getCoreStartupDateTimeAsDate(TimeZone tz)
      {
          if (coreStartupDate == null || coreStartupTime == null)
          {
              return null;
          }
  
          return DateUtil.parseDateTime(coreStartupDate + " " + coreStartupTime, tz);
      }
docs: Returns the date and time the server was started.<p>
  If either the date or time property is <code>null</code> (e.g. on Asterisk prior to 1.6.3) this method
  returns <code>null</code>.
  
  @param tz the time zone of the Asterisk server, <code>null</code> to use the default time zone.
  @return the date the server was started or <code>null</code> if not available.
  @see #getCoreStartupDate()
  @see #getCoreStartupTime()