excel - Some dates recognized as dates, some dates not recognized. Why?

Question

Here is a list of dates:

04-22-11
12-19-11
11-04-11
12-08-11
09-27-11
09-27-11
04-01-11

When you copy this list in Excel, some of them are recognized as dates, others not, in the following manner:

04-22-11
12-19-11
11-04-11 (date)
12-08-11 (date)
09-27-11
09-27-11
04-01-11 (date)

Does anyone know why? And how to force Excel to recognize all list items as dates?

Many thanks!

Answer 1

It is caused by Excel auto-recognizing/formatting the cell contents, but in unclear/inconsistent ways. Fixing it is not that hard...

Check out this forum post:

http://www.pcreview.co.uk/forums/excel-not-recognizing-dates-dates-t3139469.html

The steps in short:

1. Select only the column of "dates"
2. Click Data > Text to Columns
3. Click Next
4. Click Next
5. In step 3 of the wizard, check "Date" under Col data format, then choose: "DMY" from the droplist.
6. Click Finish