the wording [*li-thalāth baq*]{}*ī*[*na min Shawwāl*]{} ([*third-to-last-night of Shawwāl*]{}) means the 27th of [*Shawwāl*]{}, as all such dates were given and memorized under the assumption that the month would have a total of 30 days. One could question this by arguing that, after it was noticed that a particular month had only 29 days, one could correct the dating; in such a case, the third-to-last-night of [*Shawwāl*]{} would be the 26th of [*Shawwāl*]{}. On the other hand, experienced observers of the moon can deduce the number of remaining days before a new crescent moon could be observable from the currently observed age of the moon anytime during the month. Given that the month of [*Shawwāl*]{} ended with the evening sunset on AD 775 Aug 31 or Sep 1 or Sep 2, the 26th or 27th of [*Shawwāl*]{} would then be AD 775 Aug 28/29 or 29/30 or 30/31 or Aug 31/Sep 1 (from sunset to sunset). And given that the sighting of the celestial object in question here was during the morning twilight, we can date this event to a morning of AD 775 Aug 29 - Sep 1, see also Table 1. We cannot clarify the exact date without 