[Zope] Setting Timezone on Zope2.13.20 in virtualenv

Hello! I just installed the latest zope version 2.13.20 using virtualenv. I would like to be able to set the timezone to Europe/Rome. So far, I try this in instance/etc/zope.conf: <environment> TZ "Europe/Rome" </environment> But I didn't have any success. Do you have any hint? Thanks for your help, Giampiero