This headword, with its smooth breathing, is used for the day after tomorrow or for the last day of a three-day grace period (cf. epsilon 1294). It is correctly distinguished from the same word with a rough breathing, 'belonging to the previous cycle, i.e. month or year' (web address 1), at the end of epsilon 1296 and in Hesychius (epsilon2996, 2989, 2999), but our texts of the Suda incorrectly read the smooth breathing instead of the rough at epsilon 1292, epsilon 1293 and (!) epsilon 1296. This both reflects ancient confusion and leads to modern confusion.
[1] This definition is probably an error for h( triaka\s th=s selh/nhs at Etymologicum Magnum 340.55f., 'the 30th. day of the month', i.e. the 29th., in a definition of e(/nh kai\ ne/a (cf. epsilon 1292, epsilon 1293, epsilon 1296), defined as the Athenian name for the triaka/s by Photius (Lexicon mu276.27-277.10). It may, however, suggest that the first three days of the month were a grace period for fulfilling obligations normally due on the first. The genitive e)/nhs and prepositional phrases ei)s tri/thn, ei)s e)/nhn (epsilon 1294, epsilon 1296) suggest such a period ("any time up to the third").
[2] An approximation of Aristophanes, Ecclesiazusae [Assemblywomen] 796-97, spoken by the First Man ("The Selfish Man"), with the omission of a brief interjection by the Second Man ("the Neighbour"). He suggests that the Second Man does not need to hand over his property immediately under the edict of Praxagora (588-602: web address 2). There is no mention of the month or new moon in Aristophanes.
[3] This reading is not found in our mss, which have kataqh/seis, 'you will deposit', echoing the verb used by Praxagora and the Second Man for surrendering one's goods to the state (602, 607, 769, 795). The use of the future of tugxa/nw or katatugxa/nw would be, however, fully appropriate, indeed perhaps better, in the sense of succeeding in fulfilling a goal with a little bit of luck (tau 3344, sigma 1639, eta 286); cf. A.W. Gomme, "to arrive at exactly the expected time was to some extent fortuitous and fortunate" (Commentary on Thucydides 3.488).