code: private Date extrapolateStartTimeFromScanRanges(List<ScanRangeStatus> pendingScanRanges,
                                                      List<ScanRangeStatus> activeScanRanges,
                                                      List<ScanRangeStatus> completeScanRanges) {
          Date startTime = null;
  
          for (ScanRangeStatus status : Iterables.concat(pendingScanRanges, activeScanRanges, completeScanRanges)) {
              Date queuedTime = status.getScanQueuedTime();
              if (queuedTime != null && (startTime == null || queuedTime.before(startTime))) {
                  startTime = queuedTime;
              }
          }
  
          if (startTime == null) {
              // Either the scan contained no scan ranges or no scans were ever queued, neither of which is likely to
              // ever happen.  But, so we don't return null choose a reasonably old date.
              startTime = new Date(0);
          }
  
          return startTime;
      }
docs: For grandfathered in ScanStatuses that did not include a startTime attribute extrapolate it as the earliest
  time a scan range was queued.