Excel weird behaviour with dates => text

I have a ton of cells that contain dates such as 22/12/2013. This is set automatically as Date format. And if I try to change the cell format to text (Simply because I want it to be text rather than a date so that I can read it later with PHP), the thing changes completely.

Here's how to replicate the error.

1. Write in a cell 22/10/2013
2. Change the format to TEXT
3. The original content gets changed to 41569

I need a way to fix this, because otherwise when I read the date with PHP, it gets convereted to 41569 nonetheless. But if I manage to make it text, it will be alright.