Library Spreadsheet - Return Date & Days Overdue

Hello everyone,

I am trying to help our librarian out with a spreadsheet.

Cell G2 is 'Date of Loan' - this is manually filled by the librarian

Cell H2 is 'Date of Return' - 3 week loan so have used =G3+7*(3)

Cell I2 is 'Days Overdue' - Googled this and have used a custom number range: [<0]0 "Days Remaining" ; [>0]0 "Days Overdue" ; "Today"

Whilst this works, if Cell G2 is blank then formula in H2 automatically adds in a date due to the formula (20/01/1900).

Is there a better way to do this so that if Cell G2 is empty it leaves Cells H2 and I2 empty as well?

Kind regards,

Adam