Sorting by date (different date formats)

You're probably looking at text, not dates. In order to sort them in a chronological fashion, you have to convert them to real dates first.

Depending on your system settings, you may need to replace the . in 1.1.2010 with a / like 1/1/2010. You can use a find and replace to do that.

Then use =Datevalue(A1) to convert the text in cell A1 into a date. Format the result in a date format of your choice and copy the formula down. Now you should have real dates in that column and you can sort by that column.

If that does not help, post a sample workbook and specify what the default date format is for your computer settings.