Re: [boost] [date_time] i/o formatting

It's doesn't matter. When you don't have access to the stream (as in lexical_cast, don't know about program_options), you can apply neither a facet, nor a manipulator, so there is no difference.

By default all streams use the global locale. In my applications I add the date_time facets to the global locale at program startup so e.g. lexical_cast works fine. Of course it would be even better if lexcial_cast supported locales but it is better than nothing. If the facet default was the current locale ("%x") I would only need to add the facets when I need to parse dates.