Miscellany

#include <stdbool.h>
#include <avr/pgmspace.h>

#define SecondsInYear 31536000


struct DateTime
{
	unsigned char Second;
	unsigned char Minute;
	unsigned char Hour;
	unsigned char Day;
	unsigned char Month;
	unsigned int Year;
};

unsigned char months_of_year[] = {31,28,31,30,31,30,31,31,30,31,30,31};

inline bool IsLeapYear(int year);

int NumberOfDaysTillNow(int year, unsigned char month, unsigned char day);

//Time DateAdd(time startTime, unsigned long long ticks);


inline bool IsLeapYear(int year)
{
    if (year % 4 != 0)
    	return false;
	else if  (year % 400 == 0)
		return true;
    else if (year % 100 == 0)
		return false;
    else
	 return true;
}

inline int NumberOfDaysInTheYear(int year)
{
  return(IsLeapYear(year))? 366 : 365;
}


unsigned long NumberOfSecondsTillNow(struct DateTime dateTime)
{
  //Add months
  unsigned long i,sum=0;
  for (i=0;i<dateTime.Month-1;i++)
  {
     sum+= months_of_year[i] * 86400; 
  }
  
  //add leap day if neccesary.
  sum+= dateTime.Day;
  if(IsLeapYear(dateTime.Year) && dateTime.Month>2)
     sum+=86400;
  
  sum += (dateTime.Hour * 3600); //Add hours
  sum += (dateTime.Minute * 60); //Add minutes
  sum += dateTime.Second;		//Add Seconds
  
  return sum;
}


unsigned long DateTimeToEpochSeconds(struct DateTime startTime)
{
  unsigned long result = 0;

  //Days from start of startTime.Year
  unsigned long overFlowSeconds = NumberOfSecondsTillNow(startTime);
  
  //Roll back year to 1970
  while(startTime.Year > 1970)
  {
  	
  	if(IsLeapYear(startTime.Year) == true)
		result += (SecondsInYear + 86400); //add year
	else
		result += SecondsInYear;

  	startTime.Year--;
  }
  	//Remaining seconds in second
	result += overFlowSeconds;

  return result;
}


struct DateTime EpochSecondsToDateTime(unsigned long epochSeconds)
{
	struct DateTime dateTime;
	dateTime.Year = 1970;	
	

}