Microsoft Office Tutorials and References
In Depth Information
Working with Negative Time Values
By default, Excel uses a date system that begins with January 1, 1900. A negative time value
generates a date-time combination that falls before this date, which is invalid.
One solution is to use the optional 1904 date system, which assigns the date serial number 1
to January 2, 1904. Choose File
Options to display the Excel Options dialog box. Click the
Advanced tab and select the Use 1904 Date System check box. Your negative times are now
displayed correctly, as shown in Figure 94-3.
Figure 94-3: Switching to the 1904 date system causes negative times to display properly.
Be careful if your workbook contains links to other workbooks that don’t use the 1904
date system. In such a case, the mismatch of date systems can cause erroneous results.