boost::date_time::time_input_facet throws when using %j alone

[Laurent Dupuy <pizzafroide@…>]

With a format such as "%j-%H:%M:%S", boost::date_time::time_input_facet throws an error because when using "%j", the computation of the date is:

date_type d(not_a_date_time);
if (day_of_year > 0) {
  d = date_type(static_cast<unsigned short>(t_year-1),12,31) + date_duration_type(day_of_year);
}

And t_year is 1400! I am in a situation where I need to parse such a date/time though...

Instead couldn't the computation be as follows?

date_type d(not_a_date_time);
if (day_of_year > 0) {
  d = date_type(static_cast<unsigned short>(t_year), 1, 1) + date_duration_type(day_of_year - 1);
}

If so, the result of parsing "263-08:09:10" would be "1400-Sep-20 08:09:10 UTC". (And I'm good with that.)

Test exposing the problem: ​http://coliru.stacked-crooked.com/a/16f2f96ee808afa2

[James E. King, III]

%j specifies the day of the year (which begs the question: which year?), without specifying the year, why would it be valid? It'll be interesting to see how strptime handles this for reference.

[James E. King, III]

PR is out: ​https://github.com/boostorg/date_time/pull/59

[James E. King, III]

Fix merged to master; resolved.