<P> The Gregorian calendar is internationally the most widely used civil calendar . It is named after Pope Gregory XIII , who introduced it in October 1582 . </P>
<P> The Gregorian calendar is internationally the most widely used civil calendar . It is named after Pope Gregory XIII , who introduced it in October 1582 . </P>
who was the only person allowed to adjust the calendar
who was the only person allowed to adjust the calendar
Pope Gregory XIII
Pope Gregory XIII