Google Apps Script-let for timestamping a Google Document footer
// modified from http://binarywaste.blogspot.co.uk/2013/06/google-docs-inserting-date-in-footer.html
function timeStampFooter() {
var doc = DocumentApp.getActiveDocument();
var footer = (doc.getFooter()) ? doc.getFooter() : doc.addFooter();
footer.setText("");
var divider = footer.appendHorizontalRule();
var footerText = footer.appendParagraph('Confidential and Proprietary + Accessed ' + new Date());
footerText.setFontSize(9);
footerText.setForegroundColor('#4a86e8');
footerText.setAlignment(DocumentApp.HorizontalAlignment.RIGHT);
return doc;
}