Russian (?) translation: na den rojdenia

A Russian friend of mine sent a photo named ‘na den rojdenia’. What does it mean?

Literally, ‘on day [of] birthday’.

If the friend was sending you birthday greetings for your birthday, the grammar would be different. So I’m guessing it’s a pic of your friend at their/ someone else’s birthday party.

And yes, Russian.

That makes sense. My friend is originally from Moscow, and it’s her birthday. The photo was of her.

Thanks.

I believe grammatically correct way of phrasing “at” would be “na dne rojdenia”. The prepositional case declension of “den” is “dne”. “Na den rojdenia” is literally “for the birthday”, most likely referring to the gift given for someone’s birthday.