code: public void setParamTabWpTimeWarp(String value) {
  
          long datetimestamp = CmsContextInfo.CURRENT_TIME;
          // check for "delete value"
          if (CmsStringUtil.isNotEmpty(value) && !"-".equals(value)) {
              try {
                  datetimestamp = CmsCalendarWidget.getCalendarDate(getMessages(), value, true);
              } catch (Exception e) {
                  // reset timewarp setting in case of exception
              }
          }
          m_userSettings.setTimeWarp(datetimestamp);
      }
docs: Sets the "user timewparp" setting.<p>
  
  To delete a timewarp setting for the current user, provide <code>"-"</code> as value.<p>
  
  @param value a String representation of an date in the formate as required by
  {@link CmsCalendarWidget#getCalendarDate(org.opencms.i18n.CmsMessages, String, boolean)}