Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.

Class I. Words Expressing Abstract Relations
Section VI. Time
3. Time with reference to an Effect or Purpose

134. Occasion.

   NOUN:OCCASION, opportunity, opening, room, scope, space, place, liberty, show [colloq., U. S.]; suitable time, suitable season, proper time, proper season; high time; opportuneness &c. adj.; tempestivity [obs.].
  nick of time; golden opportunity, well-timed opportunity, fine opportunity, favorable opportunity; clear stage, fair field; mollia tempora [L.]; spare time (leisure) [See Leisure].
  CRISIS, turn, emergency, juncture, conjuncture; turning point, given time.
   VERB:IMPROVE THE OCCASION; seize [See Taking] an opportunity or an occasion; use [See Use] an opportunity or an occasion; give [See Giving] an opportunity or an occasion.
  suit the occasion (be expedient) [See Expedience].
  strike the iron while it is hot, battre le fer sur l’enclume [F.], make hay while the sun shines, seize the present hour, take time by the forelock, prendre la balle au bond [F.].
   ADJECTIVE:OPPORTUNE, timely, well-timed, timeful [obs.], seasonable, tempestive [archaic], timeous [rare].
  lucky, providential, fortunate, happy, favorable, propitious, auspicious, critical; suitable [See Agreement]; obiter dicta [L.].
  OCCASIONAL, accidental, extemporaneous, extemporary; contingent (uncertain) [See Uncertainty].
   ADVERB:OPPORTUNELY &c. adj.; in proper time, in proper course, in proper season; in due time, in due course, in due season; for the nonce; in the nick of time, in the fullness of time; all in good time; just in time, at the eleventh hour, now or never.
  BY THE WAY, by the by; en passant [F.], à propos [F.]; pro re natâ [L.], pro hac vice [L.]; par parenthèse [F.], parenthetically, by way of parenthesis; while on this subject, speaking of; par exemple [F.]; extempore; on the spur of the moment, on the spur of the occasion; on the spot (early) [See Earliness].
  1. Carpe diem.—Horace
  2. Occasionem cognosce.
  3. One’s hour is come, the time is up.
  4. That reminds me.
  5. Bien perdu bien connu.
  6. È sempre l’ora.
  7. Ex quovis ligno non fit Mercurius.
  8. Nosce tempus.
  9. Nunc aut nunquam.
  10. There is a tide in the affairs of men Which taken at the flood, leads on to fortune.—Julius Cæsar
  11. The Moving Finger writes; and, having writ, Moves on.—Omar Khayyám—Fitzgerald