Finding the Dates for Minimums and Maximums

Michael has some data in two columns of a worksheet. Column A is a series of dates and column B contains expenditures for each of those dates. He needs a way to determine the date on which the minimum expenditure occurred and a way to find the date on which the maximum expenditure occurred.

At first glance you might be tempted to think you could use VLOOKUP to figure out the desired date. Unfortunately, that won't work because VLOOKUP keys off of whatever data is in the first column of your data table. Since you want to key off of the amount (looking for the minimum and maximum), you would need to switch the position of the columns, so that column A contained the amount and column B contained the dates. If you do that, you could then use the following formulas to find the dates for the minimum and maximum expenditures, respectively:

=VLOOKUP(MIN(A:A),A:B,2,0)
=VLOOKUP(MAX(A:A),A:B,2,0)

If you cannot change the data columns, then you'll need to forego VLOOKUP and use a different approach, instead. The following two formulas will work with the data as originally specified by Michael:

=INDEX(A:A,MATCH(MIN(B:B),B:B,0))
=INDEX(A:A,MATCH(MAX(B:B),B:B,0))

It is important to note that if there are duplicates of the maximum and/or minimum expenditures, these formulas will only find the dates of the first occurrences. If this is not expected to happen often, a formula such as this could be used to alert the user to the existence of duplicates:

=IF(COUNTIF(B:B, MAX(B:B))>1, "Multiple Maximums ",
INDEX(A:A, MATCH(MAX(B:B), B:B, 0)))

To make this formula work for minimums, just replace the two instances of MAX with MIN and change the word "Maximums" to "Minimums."

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (9661) applies to Microsoft Excel 97, 2000, 2002, and 2003. You can find a version of this tip for the ribbon interface of Excel (Excel 2007 and later) here: Finding the Dates for Minimums and Maximums.