I have a reference table comprising a column of dates in ascending order and a column of readings (numbers in no order). Each date has a corresponding reading eg 5Apr11 = 1000. In my worksheet I have an input date, tolerance and number eg 1Apr11, 5, 1007.

For the inputted data, I would like to show the date corresponding to the closest number in the reference table that occurs after the input date and is within the +/- tolerance.

What formula would achieve this?

Thanks in advance for your reply.