Thanks from myself and my colleague. That's fixed it.

"Fred Smith" wrote:

One of your spreadsheets is set up for the 1900 date system, the other is
the 1904 date system. Change them to be the same
(ToolsOptionsCalculation1904 date system).

Regards,
Fred.

"E" wrote in message
...
I am copying a date from one file to another. The date is 01/01/2009, with
date number 39814. When I copy this to the other file the number is still
39814, but the date appears as 02/01/2013. Please could you explain why
the
date has changed when I cannot see a difference, and recommend how I can
fix
this.