Looking closer, the signature of the dial is exactly "Ian van Sÿchen Ft Gandaui 5ien 24". So "Gandaui" is "Gandavi" because at that period, the alphabet had only 23 letters (u and v are the same letters). The name for the city of Ghent (Gent) is here Gandavi, probably a diminutive of Gandavum, the latin name given by Blaeu in the map of the city published in 1650. The inscription "5ien 24" is certainly for "51en 24" but we do not know why the "en" means...The monolatitude sundials have mainly been produced between 1650 and 1700. Last point, the sundial has a tiny round hallmark along the edge near noon (XII), it is a "recense" mark used in Belgium between 1831 and 1868 applied on old objects and for reselling them at that period