code: protected void hidePopup() {
  
          if (CmsDateConverter.validateTime(getTimeText())) {
              // before hiding the date picker remove the date box popup from the auto hide partners of the parent popup
              if (m_autoHideParent != null) {
                  m_autoHideParent.removeAutoHidePartner(getElement());
              }
              m_popup.hide();
              if (m_previewHandlerRegistration != null) {
                  m_previewHandlerRegistration.removeHandler();
              }
              m_previewHandlerRegistration = null;
          }
      }
docs: Hides the date time popup.<p>