How is mautic.lead.field.timezone value obtained?

I am curious to know how the contact field mautic.lead.field.timezone is supposed to work. My anonymous UK contacts have this field automatically set to ‘Europe/Paris’. Anonymous international contacts have other values, but I’m not sure how accurate they are.

My server environment is set to UTC and my PHP is set to London/Europe. I would not think this has any relevance to how mautic.lead.field.timezone is calculated. More likely the IP Lookup service. I am using MaxMind GeoLite2 City Download. Perhaps this is not accurate enough? I have tracking set to anonymise IP.

I’m also interested in getting an aswer to this. In my case the enviroment is set to Europe/Vienna but in contacts Europoe/Helsiniki is showing up.