This is the 570th most frequent Greek word.
ημέρας
The Greek word "ημέρας" means "of the day" or "day's" (genitive singular form of "ημέρα").
In this sentence, "ημέρας" is used in its genitive singular form to indicate possession, expressing "of the day."
Η ομορφιά της ημέρας είναι μοναδική.
The beauty of the day is unique.
Here, "της ημέρας" in genitive singular denotes the time span being referred to, specifying "of the day" within the phrase "during the day."
Στη διάρκεια της ημέρας, ο ήλιος λάμπει.
During the day, the sun shines.
In this context, "της ημέρας" is again in the genitive singular form to represent possession or association, meaning "of the day."