 Instructions on the use of his sundials were given by Etzlaub in "Codex ad Compastum Norembergensem" which was kept by "Staatsbibliothek," Munich, Germany, but seems lost.Those were calendars to be hanged on the wall, giving festive days, new and full moon, some planet's positions and hints on healthcare like best times for blood-letting.They show up since 1515.