C5 BCE. See generally OCD(3) s.v. (by K.J. Dover) bibliographically updated in OCD(4). This Suda entry = Epicharmus testimonium #1 Kassel-Austin.
[1] See phi 609.
[2] Or Lykophron (Kaibel). But see Lyco 14 White.
[3] According to Diogenes Laertius 8.78, Epicharmos himself recorded that he arrived in Sicilian Megara from Kos when only three months old, and went from there to Syracuse.
[4] Little-known names, though for Myllos (sic) see Kassel-Austin, PCG 7.28.
[5] Not a plausible thing to claim about a writer whose dialect was Sicilian Doric! Other versions have him inventing two of the consonants (theta and chi, pi and psi).
[6] Probably the so-called auxanomenos logos. To quote Pickard-Cambridge (below) 250-251, 'Epicharmus, we are told, used, and in fact invented, the auxanomenos logos.- the "fallacy of the sorites" of later logicians, so called from the use of a heap of corn (soros) as the favourite illustration of it. (How many grains of corn must be taken away before a heap of corn will cease to be a heap? What if that number less one be taken away? And so on -- cf. omicron 973.) Epicharmus applied it to personality. How much change will make a man a different person? And he appears to have argued that a debtor who borrowed money yesterday does not owe it today, since he is already a different man from the borrower; and that the man whom you invited yesterday to dinner may be turned away when he arrives today, "for he is another".'

[1] Same or similar material in other lexica; references at Photius phi280 Theodoridis.
[2] This verb, also noted in other lexica, is reckoned to be attested in comedy: Comica adespota fr. 1191 Kock, now 685 K.-A.
[3] From glosses on Herodotus 3.98.4, where the phrase formou= tro/pon occurs.

See generally A. Koerte in RE 20.1, cols 540-541, under 'Phormis'; K.J. Dover in OCD(4) 1141, under 'Phormis (or Phormus)'; Kassel-Austin, PCG vol. I pp.174-176. The Suda's version of the name is also found in Athenaeus (see note 6 below) and Themistius (Or. 27.337b), who knows of him from Aristotle (Poetics 1449b6?). An Arcadian named Phormis of Maenalus, who fought as a general in Sicily for Gelon and Hieron (Pausanias 5.27.1,7), was perhaps confused with him (if not the same man).
[1] epsilon 2766.
[2] Tyrant of Gela 491-485 and of Syracuse 485-478.
[3] The [sc. Trojan] Horse and The Sack of Troy appear be alternative names for the same play. The number of his plays is thus six including the Atalanta. See Pickard-Cambridge 289 n.2.
[4] The last three titles refer to the same play. Kepheus was the father of Andromeda, who was rescued by Perseus after he had severed the head of the gorgon Medusa; cf. pi 1786.
[5] The skhnh/ was a tent or booth-like structure (later a stage building) used both as a backdrop to the stage and as a place where an actor could change and make his entrance and exit. See e.g. Plato Laws 817C (web address 1).
[6] Athenaeus, Deipnosophists 14.652A [14.66 Kaibel]; plural there, in fact.