"The worker eats two eggs a day."

[simon352104]

the phrase "a day" in English should also include the translation "κάθε μέρα" in this example, or no?

[D_..]

Given that there is better word-for-word matching I'd say no. In this context, I do this:

per day = ανά ημέρα

a day = τη μέρα / την ημέρα

every day = κάθε μέρα

[fotiosgaridis]

I agree. In this context doesn't suit to use κάθε μέρα.

[ThaliPotter]

Ο εργαζόμενος τρώει δύο αυγά την ημέρα. it is correct