Condition IF for when a calendar day is equal to a number

I have a date in a cell set to display only the day. For example, if the date is March 3, 2020 it only shows 3. Then I need to apply an IF function for when a number matches that calendar day. But the sheet does not take the coincidence because it interprets that the "3" is actually "March 3, 2020". How can I make it interpret only the number displayed (3) and not the entire date? Thank you