Translation:Usually, we would finish up before dark.
I'm a bit confused here: the 'correct' English translation seems to be conditional and lacks any sense of the past tense.
I would say the "Usually, we would finish before dark" is actually the translation of "Normalment, nous finirions avant la nuit."
I agree. Native English speaker - we do not say before night. We say before night fall.
The phrase 'finish up' isn't standard English. It should state simply 'finish', it perhaps 'finish work'
Why is "nighttime" rejected? It does not make sense to translate "avant la nuit" into "before the night".