in - before months, years (in May, in June, in 2005)Originally Posted by IARA SANTOS
on before days (on the first, on the second, on the twenty fifth, eyc)
This invoice was paid on January 23rd - you say on because you have narrowed down the date to the actual day.
You can even skip on and say it was paid January 23rd.
The invoice was paid in January. ( no day mentioned)