Hi Christiaan,
There are a bunch of files stored by region in the following directory:
/usr/share/zoneinfo
Take a look and find the one which matches your region. Then you have to create a symlink from /etc/localtime
In this case since its Amsterdam, we can follow the below steps,
# rm -f localtime
# ln -s /usr/share/zoneinfo/Europe/Amsterdam /etc/localtime
# /etc/init.d/ale-jwebapp restart
Regards,
Vishnu