Sterling Silver Saxon pocket sundial

Reputedly the oldest pocket timepiece in the world! Sterling Silver 925 and gilt replica of a Saxon pocket sundial (10th century) found in the cloisters in 1938. The months are arranged in pairs, six on either side of the sundial, with two spots marked on each. Insert the pin into the hole appropriate to the month and hang the sundial facing the sun: the shadow of the pin will reach the lower spot at 12 noon, the upper at 9 am and 3 pm. These are the hours of tierce, sext and nones, the monks' offices during the working day. This timepiece fits chronologically with the life of St. Dunstan, Archbishop of Canterbury, patron Saint of silversmiths; coincidence?
Made in England. 2"/5 cms long. Birmingham hallmark.