Why February 5, 2008?

First Quarter of 2008 gives web hosts and open source PHP projects ample time to ensure that they are ready for modern PHP development. By then PHP 5.2 will have been out for over a year and a half as well.

We wanted a date that was soon enough that PHP developers could begin planning for it but sufficiently far away that web hosts had a fair and reasonable amount of time to upgrade their systems. Why that date specifically? Because in European format it is 5/2/2008, so we can target 5.2 on 5/2.