เลขอักษร

thumb|upright=1.3|Chronogram on the Belfry of Thuin in Belgium: " reæDIfICor baptIstæ CherMan̄e soLertIa" thumb|Portrait of Henry van Gameren, with Chronogram A chronogram is a sentence or inscription in which specific letters, interpreted as numerals (such as Roman numerals), stand for a particular date when rearranged. The word, meaning "time writing", derives from the Greek words chronos (χρόνος "time") and gramma (γράμμα, "letter").