Parsing date and time with custom patterns is possible via input facets, but it's a bit cumbersome. I suppose, that developers usually writes their own functions like this: ptime pt = parse_date_time(str, format); I think, that these functions should be incorporeted in the library. Maybe there are better syntaxes. For example: ptime pt = ptime::parse(str, format); ptime pt = lexical_cast<ptime>(str, format); The same probably applies to formating output. But in that case the user can take individual elements of the value and format them with boost::format for example. I can help with implementing these functions once the proper syntax would be arranged. What do you think? Regards, Vaclav