There's 100+ locations for which we cannot determine the timezone by our current means, mostly tiny islands or locations close to a border.

Possible ways to address this:

• consider the country of the location we have nowadays (could resolve border issues)
• consider the timezone infromation from Wikidata if it is specified as IANA zone id rather than UTC offset (it rarely is, but that could allow us to manually resolve the remaining issues by adding the necessary properties on Wikidata).