Need to set my sytem clock to UTC for two reasons: 1) Dual booting Windows and Ubuntu - Windows interprets hardware clock as local time, while Linux interprets hardware clock as UTC. To sync a shared file system between the two OSes, everything apparently must be defined as UTC. 2) UTC does not use Daylight Saving Time - this would have caused severe continuity and synchronization problems when monitoring and storing long term time series data. So, my system (hardware and both OSes, + InFluxDB, Grafana, Python etc.) need to have EVERYTHING defined in UTC, but my real-life friends and contacts, and therefore my calendar and email functions need to operate in Norwegian time (UTC + 1 hour + Daylight Saving). Was SO pleased to find an Option setting that displays my Lightning calendar in UTC+1+DS, without affecting the OS settings. However, the emails are still displayed with plain UTC. Have not found any separate clock or TimeZone setting for Thunderbird - why does only Lightning, and apparently not Thunderbird, observe the Thunderbird TimeZone Option setting? How could this be resolved?