Bugreport filed to Boost date-time (prime suspect to_posix_string()). Thanks for giving a second opinion n Mats Från: Leon Mlakar [mailto:leon@digiverse.si] Skickat: den 28 december 2018 23:37 Till: Mats Webjörn/WIKAB; 'boost-users@lists.boost.org' Ämne: Re: SV: [Boost-users] Question on Posix timezone string On 28.12.2018 22:30, Mats Webjörn/WIKAB wrote: Hi Leon, Yes, but the problem is that the offset for Berlin in Boost date_time_zonespec.csv is +01, not -01 Just to avoid ambiguity - it's probably not the date_time_zonespec.csv entry that is broken (local system may use any notation they wish), and from what I saw Boost.DateTime does not claim that this file has contains Posix strings. Quite the opposite, the documentation on the offset field is very explicit: - GTM offset: This is the number of hours added to utc to get the local time before any daylight savings adjustments are made. Some examples are: America/New_York offset -5 hours, and Africa/Cairo offset +2 hours. The format must follow the length-of-time format described above. On the other hand, the documentation for to_posix_string() method does claim that it, in accordance with its name, returns a Posix compliant string. Cheers, Leon