You forgot to type in the slants.

What you've got is the 101408th day in Excel's calendar, which is 22nd
August 2177.
If you've got a lot of data where you forgot the slants, you can convert
with Data/ Text to Columns if you tell it (at the 3rd stage of 3 in the
wizard) that you want the data to be interpreted as dates in MDY format.
--
David Biddulph

Mary Put wrote:
How do I format cells so that when I put in a number it automatically
changes it to a date? I set up the cells using
Format-Number-Date-03/14/01. But when I type in 101408 the cell
shows 08/22/77. What am I doing wrong??