Three tombstones discovered in Ghor es-Safi (Byzantine Zoara) provide an explicit date for one of the Cyril Quakes. All three state that the victims died "during the earthquake". The chronological information can be summarized as follows:

• All three tombstones specify the same calendar date: 28 Artemisios, which corresponds to 18 May.


• All three specify the year 258 of the Era of Provincia Arabia calendar, which ran from 22 March 363 to 21 March 364 CE (calculated using CHRONOS). This fixes the event to 18 May 363 CE.


• Two tombstones also specify Monday as the day of the week, while the third does not. However, 18 May 363 CE in the Julian calendar fell on a Sunday and 19 May 363 CE fell on a Monday (using CHRONOS). Such inconsistencies are not unusual. Meimaris and Kritikakou (2005:51) note that 47 out of 151 epitaphs from Ghor es-Safi record a day of the week incompatible with the date, and that "these incongruities are more frequent from the early fourth until the early fifth centuries."

The individual tombstone inscriptions record the following:

• Siltha and Kyra died during the earthquake on 28 Artemisos (18 May). No day of the week is specified.


• Obbe died during the earthquake on Monday, 28 Artemisos (18 May).


• Samakon died during the earthquake on Monday, 28 Artemisos (18 May).

The Letter attributed to Cyril of Jerusalem states that the earthquake struck on Monday, 19 Iyyar . This corresponds to Monday 19 May. This creates a potential discrepancy of one day if only the calendar date is considered: 18 May in the tombstones vs. 19 May in Cyril’s letter, but no discrepancy if the day of the week is used: Monday in the tombstones vs. Monday in Cyril’s letter.

The discrepancy could be resolved if the day of the week was reckoned in Safi using the same A.G. calendar convention used in Cyril’s letter, while the calendar date was reckoned according to the standard of the Julian calendar.

In the A.G. calendar and many local Near Eastern calendars, the new day began at sundown, whereas in the Julian calendar the new day began at midnight. According to Cyril’s letter, the first earthquake struck around 10:30 pm (the third hour of the night) on Monday 19 Iyyar, i.e. Monday 19 May. If the date is instead reckoned according to the Julian calendar, that moment would fall on 18 May. If the day of the week, however, was counted using a sundown-based system, the day would be Monday. Such a reckoning could account for the tombstones’ combined date and weekday: Monday, 18 May.

Under this interpretation, the first shock of the southern Cyril quake occurred around 10:30 pm on 18 May 363 CE, causing deaths at Safi and extensive damage in Jerusalem. It would have been followed by the northern shock at about 4:30 am (the ninth hour of the night) on 19 May 363 CE.

Left - Tombstone of Samakon. Middle - Tombstone of Siltha and Kyra. Right - Tombstone of Obbe. - Click on any image to open in a new tab. - Photo on left by Jefferson Williams. Photos in Middle and Right from Meimaris and Kritikakou (2005)