src/date_func.h

   1 /*
   2  * This file is part of OpenTTD.
   3  * 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.
   4  * 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.
   5  * 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/>.
   6  */
   7
   8 /** @file date_func.h Functions related to dates. */
   9
  10 #ifndef DATE_FUNC_H
  11 #define DATE_FUNC_H
  12
  13 #include "date_type.h"
  14
  15 extern Year      _cur_year;
  16 extern Month     _cur_month;
  17 extern Date      _date;
  18 extern DateFract _date_fract;
  19 extern uint16 _tick_counter;
  20
  21 void SetDate(Date date, DateFract fract);
  22 void ConvertDateToYMD(Date date, YearMonthDay *ymd);
  23 Date ConvertYMDToDate(Year year, Month month, Day day);
  24
  25 /**
  26  * Checks whether the given year is a leap year or not.
  27  * @param yr The year to check.
  28  * @return True if \c yr is a leap year, otherwise false.
  29  */
  30 static inline bool IsLeapYear(Year yr)
  31 {
  32         return yr % 4 == 0 && (yr % 100 != 0 || yr % 400 == 0);
  33 }
  34
  35 #endif /* DATE_FUNC_H */