Boost C++ date_time microsec_clock and second_clock

Question

I discovered a strange result in Boost C++ date time library. There is inconsistency between microsec_clock and second_clock, and I don't understand why is that. I am using Windows XP 32-bits

My snip of code:

using namespace boost::posix_time;
...
ptime now = second_clock::universal_time();
std::cout << "Current Time is: "<< to_iso_extended_string(now)<< std::endl;
ptime now_2 = microsec_clock::universal_time();
std::cout << "Current Time is: "<< to_iso_extended_string(now_2)<< std::endl;
...

The print-out I expected are current time without miliseconds and with milliseonds. However, what I have in my pc is:

2009-10-14T16:07:38  
1970-06-24T20:36:09.375890

I don't understand why there is a weired date (year 1970???) in my microsec_clock time. Related documentation for Boost: link to boost date time

Newbie in Boost, any suggestion will help.

Lily

Answer 1

The 1970 date most likely comes from the way unix time is represented, as seconds from January 1 1970. I would guess that maybe it is somehow getting the system uptime in milliseconds and interpreting it as seconds since 1/1/1970. An uptime of a little over 4 hours would come up with this date.

Answer 2

Unlike second_clock, the microsec_clock::universal_time documentation mentions: Returns the UTC time based on computer settings.
You should check your hardware clock settings (or where-ever microsec gets its values from).

edit:
If its not related to your computers settings it would have to be an misbehaviour in boost, which i highly doubt.