mname = [ "jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov", "dec" ];
mlength = [ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 ];

function lowerCase(s)
{
	for(local i = 0; i < sizeof(s); i++)
	{
		if(s[i] >= 'A' && s[i] <= 'Z')
		{
			s[i] += 'a' - 'A';
		}
	}
	return s;
}
		
function day2num(date)
{
	local parts = split(date, "-");
	// find out which day of the month we have
	local days = eval(parts[0]);
	if(typeof days != "int")
	{
		message("Invalid day in " + date);
		return 0;
	}
	// make month lower case
	lowerCase(parts[1]);
	// add days from previous months
	for(local month = 0; month < sizeof mname; month++)
	{
		if(mname[month] == parts[1])
		{
			// we have found the requested month, return result
			return days;
		}
		days += mlength[month];
	}
	message("No month found in " + date);
	return 0;
}

function num2day(num)
{
	// first check validity of input
	if(num < 1)
	{
		num = 1;
	}
	if(num > 365)
	{
		num = 365;
	}
	local month = 0;
	while(num > mlength[month])
	{
		num -= mlength[month++];
	}
	// we are at the month, but we don't want "12.4-feb"
	return round(num) + "-" + mname[month];
}