Visual Basic for Applications Reference
Day Function
Returns a Variant (Integer) specifying a whole number between 1 and 31, inclusive, representing the day of the month.
Syntax
Day(date)
The required dateargument is any Variant, numeric expression, string expression, or any combination, that can represent a date. If date contains Null, Null is returned.
****Note **** If the Calendar property setting is Gregorian, the returned integer represents the Gregorian day of the month for the date argument. If the calendar is Hijri, the returned integer represents the Hijri day of the month for the date argument.