Spreadsheet vagaries

The 1904 date system and the 1900 date system

"The default date system in Excel 2004 for Mac is the 1904 date system. The default date system in Excel 2003 is the 1900 date system. Typically, the use of different date systems does not cause a problem.

However, if you transfer a workbook from Excel to Excel for Mac, or vice versa, and then copy a date from one workbook to the other, the date may increase or decrease by four years and one day. This issue occurs if the two workbooks use different date systems.

For example, if you copy the date 1/1/1998 from a workbook that uses the 1900 date system and then paste the date into a workbook that uses the 1904 date system, the date appears as 1/2/2002. Alternatively, if you copy the date 1/1/1998 from a workbook that uses the 1904 date system and then paste the date into a workbook that uses the 1900 date system, the date appears as 12/31/1993.

As long as you know about the date systems that your workbooks use, the different date systems should not cause a problem.

Labels: General, Tips, Troubleshooting