Youngest person to travel to all sovereign countries (overall)
According to Official Guinness Records,
The youngest person to travel to all sovereign countries is James Asquith (UK) who was 24 years and 192 days old when he arrived in the final country, Federated States of Micronesia, on 8 July 2013. James visited his first country outside of the UK, Lithuania, between 26 and 31 May 2001. He then visited every other sovereign country between 4 July 2008 and 8 July 2013.
Time difference between Micronesia and United Kingdom: Information about time zones and time difference between countries Micronesia and United Kingdom. The time shown here apply Daylight Saving Time when required.