To refer to a specific date, you would typically use the following format:
* "Araw ng [buwan]" (Day of [month])
* "[Bilang] ng [buwan]" ([Number] of [month])
For example:
* Araw ng Mayo (Day of May)
* 15 ng Mayo (15th of May)
"Buwan na araw" might be used in a more poetic or literary context, but it's not the standard way to express a date in everyday conversation.