I am having a hard time figuring out how to construct a ptime from a "flat" time (i.e., some number of time units since some epoch) other than a time_t. For instance, we have a lot of software here at work that represents time as a double-precision floating point number of seconds since 1/1/1904 00:00:00 GMT. As you can imagine, any sensible number is bigger than a 32-bit integer. I would like to be able to construct a ptime something like this: ptime p(date(1904, Jan, 1), microsec(boost::int64_t(float64_time * 1000000.0)); ...or even better... ptime p(date(1904, Jan, 1), float64_time); Problem is, it seems the constructors to most time_duration types use longs, even if they use int64's internally. I can't get the above example to work with any time past 12/31/1904 23:24:12, which just happens to be 0x80000000 microseconds past 1/1/1904. Another thing I would like to do is construct a ptime from a Win32 FILETIME, which is an int64 number of 100ns intervals since 1/1/1601. Something like this: ptime p(date(1601, Jan, 1), nanosec(100 * fileTime)); Is there a better way to do this? I am using MSVC 6.0 SP5 with Boost 1.31.0. -Charles