src/date_func.h

   1 /* $Id$ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   6  * OpenTTD 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.
   7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   8  */
   9
  10 /** @file date_func.h Functions related to dates. */
  11
  12 #ifndef DATE_FUNC_H
  13 #define DATE_FUNC_H
  14
  15 #include "date_type.h"
  16
  17 extern Year      _cur_year;
  18 extern Month     _cur_month;
  19 extern Date      _date;
  20 extern DateFract _date_fract;
  21 extern uint16 _tick_counter;
  22
  23 void SetDate(Date date, DateFract fract);
  24 void ConvertDateToYMD(Date date, YearMonthDay *ymd);
  25 Date ConvertYMDToDate(Year year, Month month, Day day);
  26
  27 /**
  28  * Checks whether the given year is a leap year or not.
  29  * @param yr The year to check.
  30  * @return True if \c yr is a leap year, otherwise false.
  31  */
  32 static inline bool IsLeapYear(Year yr)
  33 {
  34         return yr % 4 == 0 && (yr % 100 != 0 || yr % 400 == 0);
  35 }
  36
  37 #endif /* DATE_FUNC_H */