Sorry, but IMO you've posed two different issues here, but I won't debate you. It's Friday evening. The result of your OP for the number "1" in Excel would return 01011900 or 01011904, depending on which number system your spreadsheet is based on (1900 or 1904). Any date in Excel is just a number, and =TEXT function returns text, not strings with replaced/inserted characters. The =TEXT and =SUBSTITUTE functions are different functions altogether. Time for a shot of Bushmills... Later.