adst.h

/*
 * Auto DST support for VFD Modular Clock
 * (C) 2012 William B Phelps
 *
 * This program 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; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program 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 General Public License for more details.
 *
 */

#ifndef ADST_H_
#define ADST_H_

#include "features.h"
#ifdef HAVE_AUTO_DST

#include <Wire.h>
#include <WireRtcLib.h>

//convenience macros to convert to and from tm years 
#define  tmYearToCalendar(Y) ((Y) + 1970)  // full four digit year 
#define  CalendarYrToTm(Y)   ((Y) - 1970)
#define  tmYearToY2k(Y)      ((Y) - 30)    // offset is from 2000
#define  y2kYearToTm(Y)      ((Y) + 30)   

#define LEAP_YEAR(Y)     ( ((1970+Y)>0) && !((1970+Y)%4) && ( ((1970+Y)%100) || !((1970+Y)%400) ) )
#define SECS_PER_MIN  (60UL)
#define SECS_PER_HOUR (3600UL)
#define SECS_PER_DAY  (SECS_PER_HOUR * 24UL)

char* dst_setting(uint8_t dst);
uint8_t dotw(uint16_t year, uint8_t month, uint8_t day);
void DSTinit(WireRtcLib::tm* te, uint8_t rules[9]);
uint8_t getDSToffset(WireRtcLib::tm* te, uint8_t rules[9]);

#endif // HAVE_AUTO_DST
#endif // ADST_H