[pdf-devel] Calendar spans

[Aleksander Morgado]

Hi Jose,


I have some questions regarding Calendar Spans in the Time Module:

pdf_status_t
pdf_time_add_cal_span (pdf_time_t object,
                       const struct pdf_time_cal_span_s cal_span)

In the function `pdf_time_add_cal_span', the idea is to add to a given 
pdf_time_t (stored internally in seconds since Unix timescale origin), a 
given time span stored in a calendar way (years, months, days, and so 
on). The thing is... this calendar span should be referred to a given 
time origin, as the number of seconds in a year or in a month really 
depends on the year or the month... The only idea I have is that the 
calendar span should be referred to the time variable also passed as 
argument, so that adding the calendar span would involve converting the 
given time variable to `calendar view', then apply the calendar span and 
then back to `seconds since Unix epoch' view.


pdf_status_t
pdf_time_diff_cal (const pdf_time_t time1,
                   const pdf_time_t time2,
                   struct pdf_time_cal_span_s *p_cal_span);

And another one: Time spans represented in calendar way can't be 
negative 
(http://lists.gnu.org/archive/html/pdf-devel/2008-04/msg00017.html). So 
in functions like `pdf_time_diff_cal', how can be detected which is the 
time variable which is used as time origin for the calendar span 
returned? I can't say for example that the origin is always the first 
time variable passed.

BTW, is it really necessary/useful a time span stored in calendar way, 
taking into account that it must be referred to a given time origin?


-Aleksander