JezK
Edit File: datetime.h
/* * $Id: datetime.h,v 1.2 2000/03/11 02:14:43 chuck Exp $ * Libmcal - Modular Calendar Access Library * Copyright (C) 1999 Mark Musone and Andrew Skalski * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. * * Contact Information: * * Mark Musone * musone@chek.com * * Andrew Skalski * askalski@chek.com * * mcal@lists.chek.com */ #ifndef _DATETIME_H #define _DATETIME_H #include <time.h> #include "bool.h" /** * Represents the day of the week. */ typedef enum { SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY } weekday_t; /** * Represents the month of the year. */ typedef enum { JANUARY = 1, FEBRUARY, MARCH, APRIL, MAY, JUNE, JULY, AUGUST, SEPTEMBER, OCTOBER, NOVEMBER, DECEMBER } month_t; /** * struct datetime * * Used to represent and manipulate dates in the proleptic * Gregorian calendar. * */ typedef struct datetime { bool has_date; /* has a date value */ int year; /* year */ int mon; /* month */ int mday; /* day of month */ bool has_time; /* has a time value */ int hour; /* hour */ int min; /* minute */ int sec; /* second */ } datetime_t; #define DOE_MIN 1 /* January 1, 1 */ #define DOE_MAX 3652059 /* December 31, 9999 */ #define YEAR_MIN 1 #define YEAR_MAX 9999 #define DT_INIT { false, 0, 0, 0, false, 0, 0, 0 } /** general date/time functions **/ /* returns true if <year> is a leap year */ bool isleapyear(int year); /* returns days in <month>; if <leap> is true, gives result for leap year */ int daysinmonth(int month, bool leap); /* returns true if the date is valid */ bool datevalid(int year, int mon, int mday); /* returns true if the time is valid */ bool timevalid(int hour, int min, int sec); /*********************************/ /** datetime_t related functions **/ /* initializes <dt> with no date or time */ void dt_init(datetime_t *dt); /* fills the current date/time into <dt> */ bool dt_now(datetime_t *dt); /* clears the date portion of <dt> */ void dt_cleardate(datetime_t *dt); /* clears the time portion of <dt> */ void dt_cleartime(datetime_t *dt); /* returns true if <dt> has a date */ bool dt_hasdate(const datetime_t *dt); /* returns true if <dt> has a time */ bool dt_hastime(const datetime_t *dt); /* returns true if <dt> has no value */ bool dt_empty(const datetime_t *dt); /* sets <dt> from the fields of <tm> */ bool dt_settm(datetime_t *dt, const struct tm *tm); /* sets the date portion of <dt> */ bool dt_setdate(datetime_t *dt, int year, int mon, int mday); /* sets the time portion of <dt> */ bool dt_settime(datetime_t *dt, int hour, int min, int sec); /* returns <0, 0, >0 if a<b, a==b, a>b respectively */ int dt_compare(const datetime_t *a, const datetime_t *b); /* returns the day-of-year of <dt> */ int dt_dayofyear(const datetime_t *dt); /* returns the day-of-week of <dt> */ int dt_dayofweek(const datetime_t *dt); /* returns the day-of-epoch (1 is January 1, 1). this format has the * property that DOW==DOE%7 */ int dt_dayofepoch(const datetime_t *dt); /* sets the datetime from day-of-epoch */ bool dt_setdoe(datetime_t *dt, int doe); /* rolls the time by <hour> <min> and <sec>, spilling over into the * date if it exists */ bool dt_roll_time(datetime_t *dt, int hour, int min, int sec); /* sets <dt> to be the <wday> in the same week as <ref>, if <weekstart> * is the first day of the week. */ bool dt_setweekof( datetime_t *dt, const datetime_t *ref, weekday_t weekstart, weekday_t wday); /* sets the datetime from year, month, week and day */ bool dt_setnthwday(datetime_t *dt, int year, int mon, int nth, int wday); /* Returns the week number for d=day, m=month, y=year */ int dt_weekofyear(int d, int m, int y); /* convenience macros to get the first/last days of a week */ #define dt_startofweek(dt, ref, weekstart) \ dt_setweekof((dt), (ref), (weekstart), (weekstart)) #define dt_endofweek(dt, ref, weekstart) \ dt_setweekof((dt), (ref), (weekstart), (7+(weekstart)-1)%7) /**********************************/ #endif