Look up exact match and nearest date
AhoyNC has posted an array formula here, which you can use to look up one value that is an exact match in the array, and second value which finds the closed date in the array.
In this example we have a worksheet named Rates which shows rates on a different dates for a set of facilities.
On the main worksheet we have a customer list and want to look up the rates at different locations on particular dates.
We enter this formula to match the facilities in column C where they are paired with the dates in column B, and then designate that facilities and dates on the Rates worksheet should be paired as well. The value given after the INDEX formula is what is returned to the cell.
Press CTRL + SHIFT plus ENTER when entering this formula so that Excel recognizes it as an array formula and adds brackets around it.