The solution lies with using Excel's array feature to traverse a data list automatically and extract missing sequential numbers, even if the number list is out of order.

There are a few ways to count the number of items in an Excel list, depending on the data you have. One way is using the COUNTIF function.

If your company is working with a large list in an Excel spreadsheet, take advantage of the program's built-in filter customization tools to limit the number of rows included in your filter results.

How to return a sequence of dates in Excel Excel’s fill handle can generate a quick list of dates for you, but the list is static; you must create a new list if your needs change.