parsedate - convert time and date string to number

Parsedate does not accept all desirable and unambiguous constructions.  Semantically incorrect dates such
       as ``February 31'' are accepted.

       Daylight savings time is always taken as a one-hour change which is wrong for some places.  The  daylight
       savings  time correction can get confused if parsing a time within an hour of when the reckoning changes,
       or if given a partial date.

Parsedate  converts  many common time specifications into the number of seconds since the epoch — i.e., a
       time_t; see time(2).

       Parsedate returns the time, or -1 on error.  Text is a character string containing  the  time  and  date.
       Now  is  a  pointer to the time that should be used for calculating relative dates.  If now is NULL, then
       GetTimeInfoinlibinn(3) is used to obtain the current time and timezone.

       The character string consists of zero or more specifications of the following form:

       time   A time of day, which is of the form hh[:mm[:ss]] [meridian] [zone] or hhmm [meridian] [zone].   If
              no meridian is specified, hh is interpreted on a 24-hour clock.

       date   A  specific  month and day with optional year.  The acceptable formats are mm/dd[/yy], yyyy/mm/dd,
              monthnamedd[, yy], ddmonthname [yy], and day,ddmonthnameyy.  The default year is the  current
              year.  If the year is less then 100, then 1900 is added to it; if it is less then 21, then 2000 is
              added to it.

       relativetime
              A  specification  relative  to  the current time.  The format is numberunit; acceptable units are
              year, month, week, day, hour, minute (or min), and second (or sec).  The unit can be specified  as
              a singular or plural, as in 3weeks.

       The  actual date is calculated according to the following steps.  First, any absolute date and/or time is
       processed and converted.  Using that time as the  base,  day-of-week  specifications  are  added.   Next,
       relative  specifications  are  used.   If a date or day is specified, and no absolute or relative time is
       given, midnight is used.  Finally, a correction is applied so  that  the  correct  hour  of  the  day  is
       produced after allowing for daylight savings time differences.

       Parsedate ignores case when parsing all words; unknown words are taken to be unknown timezones, which are
       treated  as  GMT.   The  names of the months and days of the week can be abbreviated to their first three
       letters, with optional trailing period.  Periods are ignored in any timezone or meridian values.

       Originally written by Steven M. Bellovin <smb@research.att.com> while at the University of North Carolina
       at Chapel Hill and distributed under the name getdate.

       A major overhaul was done by Rich $alz <rsalz@bbn.com> and Jim Berets <jberets@bbn.com> in August, 1990.

       It was further revised (primarily to remove obsolete constructs and timezone names) a year later by  Rich
       (now  <rsalz@osf.org>)  for  InterNetNews,  and  the  name  was  changed.   This  is revision 1.10, dated
       1993/01/29.

       parsedate - convert time and date string to number

date(1), ctime(3), libinn(3), time(2).

                                                                                                    PARSEDATE(3)

#include<sys/types.h>typedefstruct_TIMEINFO{time_ttime;longusec;longtzone;}TIMEINFO;time_tparsedate(text,now)char*text;TIMEINFO*now;