Always check your data entry: out of over 2,000 entries, there's always one outlier!
Spare a thought for William Home, a seventeenth-century minister based in the Scottish Borders. Somehow, we doubt his time at Ayton ended in 664AD.
*ahem*
ALT Data entry form for Mapping the Scottish Reformation project. The bottom pane shows an entry for the parish of Ayton with an end date of 664, rather than 1664.