* All dates in appendix D were computed using HDATE, a calendar conversion programme developed by Dr Waleed A. Muhanna as part of Release 2.1 (August 1994) of his IslamicTimer© software package, which assumes the change from the Julian to the Gregorian calendar from 15 October 1582. Although most Roman Catholic countries accepted Pope Gregory XIII’s reform of the Christian calendar – dropping ten days and improving the leap-year algorithm – from that date, Britain and its colonies did not adopt it until 1752. Other European countries made the change at various times, some (for example Greece) not until the twentieth century.