sfldate.h

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/*  ----------------------------------------------------------------<Prolog>-
    Name:       sfldate.h
    Title:      Date and time functions
    Package:    Standard Function Library (SFL)

    Written:    1996/01/05  iMatix SFL project team <[e-mail]>
    Revised:    1998/08/05

    Synopsis:   Includes functions to get the current date/time, calculate
                the day or week, week of year and leap year.  Dates and times
                are each stored in a 32-bit long value of 8 digits: dates are
                CCYYMMDD; times are HHMMSSCC.  You can compare dates and times
                directly - e.g. if (date_wanted >= date_now).

    Copyright:  Copyright (c) 1996-2000 iMatix Corporation
    License:    This is free software; you can redistribute it and/or modify
                it under the terms of the SFL License Agreement as provided
                in the file LICENSE.TXT.  This software is distributed in
                the hope that it will be useful, but without any warranty.
 ------------------------------------------------------------------</Prolog>-*/

#ifndef SFLDATE_INCLUDED               /*  Allow multiple inclusions        */
#define SFLDATE_INCLUDED

/*  Macros                                                                   */

#define GET_CENTURY(d)      (int) ( (d) / 1000000L)
#define GET_CCYEAR(d)       (int) ( (d) / 10000L)
#define GET_YEAR(d)         (int) (((d) % 1000000L) / 10000L)
#define GET_MONTH(d)        (int) (((d) % 10000L) / 100)
#define GET_DAY(d)          (int) ( (d) % 100)

#define GET_HOUR(t)         (int) ( (t) / 1000000L)
#define GET_MINUTE(t)       (int) (((t) % 1000000L) / 10000L)
#define GET_SECOND(t)       (int) (((t) % 10000L) / 100)
#define GET_CENTI(t)        (int) ( (t) % 100)

#define MAKE_DATE(c,y,m,d)  (long) (c) * 1000000L +                          \
                            (long) (y) * 10000L +                            \
                            (long) (m) * 100 + (d)
#define MAKE_TIME(h,m,s,c)  (long) (h) * 1000000L +                          \
                            (long) (m) * 10000L +                            \
                            (long) (s) * 100 + (c)

#define timeeq(d1,t1,d2,t2)  ((d1) == (d2) && (t1) == (t2))
#define timeneq(d1,t1,d2,t2) ((d1) != (d2) || (t1) != (t2))
#define timelt(d1,t1,d2,t2)  ((d1) < (d2) || ((d1) == (d2) && (t1) <  (t2)))
#define timele(d1,t1,d2,t2)  ((d1) < (d2) || ((d1) == (d2) && (t1) <= (t2)))
#define timegt(d1,t1,d2,t2)  ((d1) > (d2) || ((d1) == (d2) && (t1) >  (t2)))
#define timege(d1,t1,d2,t2)  ((d1) > (d2) || ((d1) == (d2) && (t1) >= (t2)))

/*  Days are numbered from 0=Sunday to 6=Saturday                            */

#define DAY_SUNDAY      0
#define DAY_MONDAY      1
#define DAY_TUESDAY     2
#define DAY_WEDNESDAY   3
#define DAY_THURSDAY    4
#define DAY_FRIDAY      5
#define DAY_SATURDAY    6


/*  Interval values, specified in centiseconds                               */

#define INTERVAL_CENTI      1
#define INTERVAL_SEC        100
#define INTERVAL_MIN        6000
#define INTERVAL_HOUR       360000L
#define INTERVAL_DAY        8640000L


/*  Function prototypes                                                      */

#ifdef __cplusplus
extern "C" {
#endif

long   date_now           (void);
long   time_now           (void);
Bool   leap_year          (int year);
int    julian_date        (long date);
int    day_of_week        (long date);
int    week_of_year       (long date);
int    year_quarter       (long date);
long   next_weekday       (long date);
long   prev_weekday       (long date);
word   pack_date          (long date);
word   pack_time          (long time);
long   unpack_date        (word packdate);
long   unpack_time        (word packtime);
long   default_century    (long *date);
long   date_to_days       (long date);
long   days_to_date       (long days);
time_t date_to_timer      (long date, long time);
long   timer_to_date      (time_t time_secs);
long   timer_to_time      (time_t time_secs);
long   timer_to_gmdate    (time_t time_secs);
long   timer_to_gmtime    (time_t time_secs);
long   time_to_csecs      (long time);
long   csecs_to_time      (long csecs);
void   future_date        (long *date, long *time, long days, long csecs);
void   past_date          (long *date, long *time, long days, long csecs);
void   date_diff          (long date1, long time1, long date2, long time2,
                           long *days, long *csecs);
Bool   valid_date         (long date);
Bool   valid_time         (long time);
Bool   date_is_future     (long date, long time);
Bool   date_is_past       (long date, long time);
char  *timezone_string    (void);
void   local_to_gmt       (long date, long time, long *gmdate, long *gmtime);
void   gmt_to_local       (long gmdate, long gmtime, long *date, long *time);
struct tm *safe_localtime (const time_t *time_secs);
struct tm *safe_gmtime    (const time_t *time_secs);

#ifdef __cplusplus
}
#endif

#endif