public boolean isGregorianLeapYear(int year)
	{	
		// Every year that is exactly divisible by four is a leap year
		if ((year%4)==0) 
		{
			// except for years that are exactly divisible by 100. 
			if ((year%100)==0) 
			{
				// the centurial years that are exactly divisible by 400 are still leap years.
				if ((year%400)==0)
				{
					return true;
				}
				else
				{
					return false;
				}
			}
			else
			{
				return true;
			}
		}
		else
		{
			return false;
		}
	}