Crepuscular /(-k?-l?r)/

Cre·pus·cu·lar

Crepuscular

a.
  1. Pertaining to twilight; glimmering; hence, imperfectly clear or luminous.
    This semihistorical and crepuscular period.
    — Sir G. C. Lewis.
  2. Flying in the twilight or evening, or before sunrise; -- said certain birds and insects. (Zool.)
    Others feed only in the twilight, as bats and owls, and are called crepuscular.