Crepuscular

 WORD OF THE DAY

crepuscular / adjective / krih-PUHSS-kyuh-ler

Definition
1a: of, relating to, or resembling twilight
1b: dim
2: occurring or active during twilight

Examples
"Cardinals, a crepuscular species, follow their own schedule, eating an early breakfast and a stylishly late dinner. They will break that schedule on very cold days."
— Jim Williams, The Star Tribune (Minneapolis, Minnesota), 16 Feb. 2022

For instance, ungulates, such as bison, and coyotes are generally crepuscular, or most active at dusk and dawn, whereas alligators are diurnal and nocturnal.
— Andrea Sachs, Washington Post, 22 June 2022

Did You Know?
The early Romans had two words for the twilight
. Crepusculum was favored by Roman writers for the half-light of evening, just after the sun sets; diluculum was reserved for morning twilight, just before the sun rises—it is related to lucidus, meaning "bright."
We didn't embrace either of these Latin nouns as substitutes for our word twilight, but we did form the adjective crepuscular in the 17th century.
The word's zoological sense, relating to animals that are most active at twilight, developed in the 19th century.