gpstracker-firmware/GpsTracker/Time2.h

#pragma once

#include <Arduino.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)

/*============================================================================*/

	typedef unsigned long timestamp_t;

	typedef struct {
		uint8_t Second;
		uint8_t Minute;
		uint8_t Hour;
		uint8_t Wday;   // day of week, sunday is day 1
		uint8_t Day;
		uint8_t Month;
		uint8_t Year;   // offset from 1970; 
	} 	tmElements_t, TimeElements, *tmElementsPtr_t;

	/* low level functions to convert to and from system time                     */
	void breakTime(const timestamp_t time, tmElements_t &tm);  // break timestamp_t into elements
	timestamp_t makeTime(const tmElements_t &tm);  // convert time elements into timestamp_t

	tmElements_t operator += (const timestamp_t b) {

	}

	tmElements_t operator + (const tmElements_t a, const timestamp_t b) {
		tmElements_t result;
		timestamp_t aTimestamp = makeTime(a);
		breakTime(aTimestamp + b, result);

		return result;
	}