Re: [Boost-users] [date_time]time zone input

2 Oct 2006


      Sean Huang wrote:
...
----- Original Message ----- 
From: "Jeff Garland" 
To: 
Sent: Sunday, October 01, 2006 8:03 PM
Subject: Re: [Boost-users] [date_time]time zone input
...
...
That would be great. What we are trying to do is to convert DICOM DT 
(Date
time) element to boost::date_time and it is in the format shown below:
YYYYMMDDHHMMSS.FFFFFF&ZZZZ
One way I can think of is treat the string as posix time and parse the
time-zone offset part ourselves. It sounds like there are better ways to
accomplish this. I would appreciate it very much if you could point me to
the right direction.
That's exactly what I would suggest, although actually you can probably 
parse
it into a time_duration.
Can you elaborate on this a bit more?
See below.
...
I just use it to do a one-time adjustment. I agree with you that the 
aforemented format does not fully specify a time zone (I guess I used the 
wrong subject in the first place. :-)). DICOM only uses the ZZZZ as the 
offset from UTC and that's how we plan to use ZZZZ. We'll convert it to UTC 
time as soon as it is parsed.
Ok, easy as pie.  We'll set the time_duration_format format, stream it in and 
convert to utc:

     try {
       //setup your input facet
       time_input_facet *facet = new time_input_facet();
       facet->set_iso_format();
       facet->time_duration_format("%H%M"); // just get a tz parts
       some_stream_instance.imbue(std::locale(std::locale::classic(), facet));

       //stream the parts in
       ptime t;
       time_duration td(0,0,0);

       //get the time part
       t >> some_stream_instance;
       //now get the utc offset
       td >> some_stream_instance;
       t += td; //convert time to UTC
     }
     catch(std::exception& e)

I didn't compile or run this...you'll what some error handling...but I'm 99% 
sure it will do what you want :-)

Jeff