DEbian挤压升级PHP 5.3到PHP 5.5

On Debian (Squeeze), I need to upgrade from PHP 5.3 to PHP 5.5.

I tried those commands : apt-get update; apt-get install php5;

also adding :

echo "deb http://packages.dotdeb.org squeeze all" >> /etc/apt/sources.list
echo "deb-src http://packages.dotdeb.org squeeze all" >> /etc/apt/sources.list

But nothing change, it's still PHP 5.3. Any ideas ? Thanks

I don't think that Dotdeb has PHP 5.5 for Debian 6 Squeeze. The latest version I can see is 5.4.

They have PHP 5.5 only for Debian 7 Wheezy.

Not many people have squeeze now. Did you try http://forums.debian.net/viewtopic.php?f=30&t=108694? They advice

apt-get install php5 -t squeeze-php54 -s

I would try squeeze-php55, and if it works, then without -s