The EDATE Function

Re. my most recent comment below, if your version of Excel includes REGEXREPLACE, that function takes precedence and My Excel Toolbox's RegExReplace cannot be referenced. Therefore, the original RegExReplace was renamed RegExSubstitute. A legacy version of RegExReplace was retained; it simply calls RegExSubstitute using the same parameters.
See https://sites.google.com/view/MyExcelToolbox/

@ J. Woolley: thanks very much, I'll take a look at that.

@Kiwerry
My Excel Toolbox includes the following regular expression functions:
    =IsRegEx(Text,Pattern,[IgnoreCase],[Multiline])
    =RegExMatch(Text,Pattern,[Mode],[IgnoreCase],[Multiline])
    =RegExReplace(Text,Pattern,Replacement,[Instance],[IgnoreCase],[Multiline])
These functions use the VBScript 5.5 regular expression syntax described here: https://learn.microsoft.com/en-us/previous-versions/1400241x(v=vs.85)
and https://drive.google.com/open?id=1qWS2qLib0sL_u6Sh95FuEeZxRzzr4SUE
They are similar to the new Excel functions REGEXTEST, REGEXEXTRACT, and REGEXREPLACE described here: https://insider.microsoft365.com/en-us/blog/new-regular-expression-regex-functions-in-excel
See https://sites.google.com/view/MyExcelToolbox/

@ J. Woolley: Thanks very much for the link, looks like a useful reference.

I guess my suggestion has its roots in my having received a number of emails from various Excel sites about the new REGEX functions; it's frustrating to read about something interesting, only to find that it isn't yet available (Excel 365).

@Kiwerry
You might be interested in this site: https://exceljet.net/functions
It conveniently identifies the Excel version for every built-in function. A search for EDATE indicates Excel 2003.

Re. EDATE(date, months) the Tip says, "The date parameter you use should resolve to a date serial number and not be a textual date."
Excel's DATEVALUE(date_text) converts a textual date into a date serial number. However, DATEVALUE thinks the 21st century ends after 2029, so
DATEVALUE("12/25/30") returns 12/25/1930 instead of 12/25/2030 as might be expected. This could be a problem for the current and future decades.
The following Microsoft article discusses Excel dates:
https://support.microsoft.com/en-us/office/change-the-date-system-format-or-two-digit-year-interpretation-aaa2159b-4ae8-4651-8bce-d4707bc9fb9f
Under the heading "Change the way two-digit years are interpreted," some issues are worth considering (with respect to region "United States"):
For the Windows 10 procedure to "change the way two-digit years are interpreted for all Windows programs that you have installed," in step 1 you should search for "region" instead of "control panel" and select Region, then skip steps 2 and 3 and continue with step 4. Let's assume you "change the upper limit for the century" to 2049 (for example). Now when you type 12/25/30 into a cell the date will be 12/25/2030 and typing 12/25/50 will produce 12/25/1950. However, Excel's DATEVALUE function ignores this change to the Windows Region Calendar; it still thinks the 21st century ends after 2029.
It is worth noting that VBA's DateValue function recognizes a change to the century upper limit appropriately, so VBA.DateValue("12/25/30") returns 12/25/2030 (for this example). Therefore, My Excel Toolbox includes the DATEVALUE2 function to address this issue. Here is an abbreviated version:
    Function DATEVALUE2(Date_Text As String) As Date
        DATEVALUE2 = DateValue(Date_Text)
    End Function
See https://sites.google.com/view/MyExcelToolbox/

Especially useful for getting the last day number of a month from a date in a cell
But there is also the DATE() function that takes year, with month numbers that can be positive, or negative offsets from the first day of the year, and day numbers that can also be negative offsets from the first day of the calculated month.
so DATE(1900+years,month+monthoffset+1,-1) is an EOMONTH of the month+monthoffset month

All within the excel date range - as in year calculated, or specified not being before 1900, or 1904
and the month not being FEB or MARCH of the first allowed year, be it 1900 or 1904

Yes there is a 29th Feb in 1900 according to Excel,
but not according to accurate calendars.

Thank you Allen.
May I suggest that tips describing a function include a short mention of the first version of Excel which has the function, or its status, if it's still a beta version not widely available?

Why? Reading about an interesting looking function, only to find it's not available, is counterproductive. This doesn't apply to the EDATE function described above, which has been around for a long time, but there are a number of functions introduced in more recent years to which it would apply.

Thanks for your attention and keep well.