Learn Farsi: اواخر روز، نزدیک غروب، هلال ماه خیلی زیبا است. - Late in the day, near sunset, the crescent moon is very beautiful.

avâkher is the Arabic broken plural of âkhar (end). In Farsi, these broken plurals—like avâkher (late), avâyel (early), and avâset (mid)—are used to express temporal sub-divisions. Instead of pinpointing a single exact moment, they describe a span or phase of time. Thus, avâkher-e ruz translates literally as the latter parts of the day.

Could I just use the singular âkhar-e ruz instead? What is the nuance?

You could, but the meaning shifts slightly. âkhar-e ruz refers to the absolute, specific end of the day. Using the plural form avâkher-e ruz stretches the timeframe, referring generally to the later portion of the day. It represents a lingering phase, which pairs perfectly with the concept of an approaching sunset.

Why is there no preposition like dar (in) before avâkher-e ruz?

Phrases built with these temporal broken plurals often function as adverbial phrases of time all on their own. While you could technically add dar before avâkher-e, it is entirely unnecessary. The phrase naturally implies the preposition, standing alone to mean in the late part of.

Why does nazdik take an ezafe in nazdik-e ghorub? Don't we normally use the preposition be for near?

While it is true that you often see nazdik be used for physical distance or abstract closeness, usually takes an when directly modifying a specific point in time. Therefore, is the most natural way to say near sunset in Farsi.