The festival of Chag Yeshua was enacted from the 8th to the 14th of the Egyptian month of Epeiph (2Macc. 6:37-40). The Egyptian calendar was a Solar Calendar and these days correspond to 19 August 217 BCE on the Julian Calendar (Aug. 23rd Gregorian) and this was 12th Elul 3544 on the Hebrew calendar.
This is simple to check. Go to http://egypt.online-resourcen.de/Ptolemaic_Kings
Reign: Ptolomy Philopator