logback-android/src/main/java/ch/qos/logback/core/status/StatusUtil.java
public long timeOfLastReset() {
    List<Status> statusList = sm.getCopyOfStatusList();
    if (statusList == null)
      return -1;

    int len = statusList.size();
    for (int i = len - 1; i >= 0; i--) {
      Status s = statusList.get(i);
      if (CoreConstants.RESET_MSG_PREFIX.equals(s.getMessage())) {
        return s.getDate();
      }
    }
    return -1;
  }
public long timeOfLastReset() {
    List<Status> statusList = sm.getCopyOfStatusList();
    if (statusList == null)
      return -1;

    int len = statusList.size();
    for (int i = len - 1; i >= 0; i--) {
      Status s = statusList.get(i);
      if (CoreConstants.RESET_MSG_PREFIX.equals(s.getMessage())) {
        return s.getDate();
      }
    }
    return -1;
  }
Return the time of last reset. -1 if last reset time could not be found

@return time of last reset or -1