If it’s a month, in. He was born in March. If it’s a date within a month, on. He was born on March 27.
Besides, do we use the before date?
The last two date formats are more formal. The “the” and “of” are optional but if you do use them, you must add both “the” and “of.” It is incorrect to say only “6th of September” or “the 6th September.”
Similarly, what preposition should be used before month? “Before” / “After” Use the prepositions “before” and “after” to state that something happens either before or after a specific time. You can use “before” and “after” with specific times, days, years, or months: I’ll see you after class.
Beside above, do we use on or in for month?
On is used for a specific date (e.g. December 20, 2017), because it is one point in time. In is used for a month, because the month contains a time span.
Is it in or on January?
“In” is usually correct because January has 31 days, so the answer will address only some of those days. However, if you are talking about just one day and one occurrence you would say “Mary’s sixth birthday is on January 16, 2000.”