Assistance with Array Function for Date Calculation

Hi all,

I've created a spreadsheet full of formulas to work out dates for meetings and when to call for papers, etc. One of the columns is calculated from a rigid set of dates using an array formula, whereas everything else is calculated from the main input date. I need assistance to make the array function work better.

At the moment, I'm using the MAX function with <, it is picking the nearest date before the date in row K. When using MIN and >, it gives me the nearest date after row K. I'm trying to make it so that the date which appears in row D is the nearest date on the SMTDates range regardless of past or future so long as it falls between the dates in rows C and F. I've tried utilising the INDEX function, but have been unable to make that work to any great effect either.