The term "dramatic date" refers to the date given or implied in the work in question, whether or not the event actually happened. In other words, the event may be entirely fictional but it can have a precise date. In such a case, the date is part of the fiction.
440 SERVES IN SAMIAN CAMPAIGN
early 432 dramatic date of Plato, Alcibiades
432 or after LEAVES FOR POTIDAEA.
431-404 Peloponnesian War
429 RETURNS TO ATHENS FROM POTIDAEA
May 429 dramatic date of Plato, Charmides
424 at DELIUM (Athenians defeated by Boeotians)
winter 424 dramatic date of Plato, Laches
423 Aristophanes, Clouds; Ameipsias, Konnos
422 at AMPHIPOLIS Pl. Apol. 28e2.
422 dramatic date of Xenophon, Symposium
418-416 dramatic date of Plato, Phaedrus
416 dramatic date of Plato, Symposium
ca. 416 SON LAMPROCLES BORN. Apol. 34d; Phaed. 116b; Xen. Mem. 2.2.1-14; D.L. 2.29.
415 Profanation of Mysteries. Phaedrus one of those exiled.
ca. 410 SON SOPHRONISCUS BORN. Apol. 34d; Phaed. 116b
406 MEMBER OF BOULE; opposed illegal trial of generals from battle of Arginusae. Apol. 32b1-c4; Gorg. 473e6-474a1 (see Dodds n.); Xen. Mem. 1.1.18; 4.4.2; HG 1.7.15; cf. [Pl.] Ax. 368d6-369a2; Ael. VH 3.17.
404 Fall of Athens. Thirty Tyrants. SOCRATES ORDERED TO ARREST LEON OF SALAMIS; REFUSES (Apol. 32c-d; Xen. Mem. 4.4.3). SOCRATES TRIES TO SAVE THERAMENES (Diodorus Siculus 14.5; but cf. Libanius 1.57).
403 Amnesty decree passed by Athenian Assembly.
ca. 402 SON MENEXENUS BORN. Apol. 34d; Phaed. 116b. Cf. Xen. Mem. 4.4.23 on proper age for begetting children.
401 Xen. leaves Athens to join Greek mercenaries in Asia Minor.
399 TRIAL AND DEATH OF SOCRATES
394 Xen. returns to Greece with Agesilaus; lives at Scillus, near Olympia.
393-392 Polycrates, Categoria Socratis (CS) / Accusation of Socrates
366/5 Xen. returns to Athens.
*Woodbury  1991: 223-25
(interpretation of Ion of Chios FGrH 392F9).