What word means best at dawn and dusk?
the time of day before it gets dark
Crepuscolo is the literal Italian equivalent of 'dusk'. It's a masculine gender noun that may be translated as 'twilight, gloaming, dusk'. It's pronounced 'kray-POO-skoh-loh'. But another equivalent is the phrase 'sull'imbrunire', which means 'at dusk'. In the word by word translation, the preposition 'sul, sulla, sullo' means 'on the'. The infinitive 'imbrunire' means 'to turn, make or grow dark'.
You could use Aurora Lucens. Aurora is a word for dawn (diluculo doesn't have such a nice ring to it, but can also be used for dawn). Lucens is from lucere, to shine. Also: Aurora splendens, brilliance, splendor, radiant; or Aurora scintilens/scintillens, sparkling, shining, twinkling. Personally, Aurora Lucens covers best the meaning of shining if you just mean light.
In the Natick language used by the Wampanoag tribe, the word wompanniyeu means "in the east"; in Algonkin the word wabanong means "east"; in the Lenape (Delaware) language, wapaneu means "east"; Cree wapun means it is daylight. The word was originally wampanawag, meaning "people in the east", or "dawn people".