PEAR's date and time section provides three very powerful packages. Each package is well designed and helps you develop applications that are fast and effective. A big advantage of the three packages is that you can use them in combination with each other without fearing incompatibilities. Both the
Date_Holidays packages are able to use
PEAR::Date classes. PHP's native date and time functions are certainly faster but if you want an object-oriented API that is comfortable and powerful at the same time, the date packages are a very good solution.