Controlling Automatic Formatting of Dates

When Ted enters a date with just the month and day, i.e. 4/5, the date displays 5-Apr and the number format is Custom. However, when he enters 4/5/18 the date displays 4/5/2018 and the number format is Date. Ted wonders how he can get the date to format to 4/5/2018 when he enters only 4/5 without having to format the cells to Date before making his entry. In other words, he wants the date to default to Date and not Custom.

There is no way to do this within Excel. In this case, Excel, as part of its parsing process, chooses the date format that it believes you intended based upon how you entered the date. If you want to use a different date format, you must explicitly format the column (or cells) to use the date format you want before you enter the date, or you must format the column (or cells) explicitly after you enter the date.

There is one macro-based solution, but it may be a bit of overkill. All you need to do is to add this event handler to the code window for the worksheet. (Right-click on the worksheet tab and choose View Code from the resulting Context menu. Paste this short macro into the code window that then appears.)

Private Sub Worksheet_Change(ByVal Target As Range)
    If IsDate(Target) Then
        Target.NumberFormat = "m/d/yyyy"
    End If
End Sub

The macro checks whatever you enter into a cell, and if it is determined to be a date (that's the purpose of the IsDate function), then the desired date format is applied to the cell.

I mentioned that this may be a bit of overkill because you will, obviously, need to save the workbook as a macro-enabled workbook. If this is no problem for your use of the workbook, however, then it may solve your date-formatting needs.

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (13553) applies to Microsoft Excel 2007, 2010, 2013, 2016, 2019, and Excel in Microsoft 365.