Last week I had a conference call with four people in three different time zones. An app set up the call, calculated the correct time for each participant, added the appointment to each of our calendars, and then periodically sent us texts and emails so that we would not forget.
Six hundred years ago, the scheduling computer of the age was a large device made up of several intersecting wooden disks etched with marks supplying information on the hours, days and months of the year. Hanging in monasteries throughout Europe, these precision instruments were attended to daily by the monks of the cloister, providing necessary information on when to gather for prayer and what days to celebrate important feasts.
Gazing at the San Zeno Astrolabe in Now and Forever: The Art of Medieval Time, a