2. The Era of the Death of Alexander (Era of Philip)

The Era of the Death of Alexander is a proleptic pseudo-regnal era starting on 1 Thoth in the year Alexander the Great died = 12 November 324. In Ptolemy's Handy Tables, for which we have the fourth century edition of Theon of Alexandria, this era is renamed as the Era of Philip, Alexander's brother and successor. It is known to Censorinus 21.9 under this name.

This era occasionally appears in the Almagest for obversations made by Hipparchus, and Ptolemy (or his source) occasionally translates observational dates from the Era of Dionysios into this era. The fact that it appears in Hipparchan dates sugest that it was in use in Hipparchus' lifetime, although most Hipparchan dates are Callippic.

3. The Era of Dionysios

The Era of Dionysios is known solely from the Almagest, and