//gets difference of years from 2 dates

function year_diff(date_from,type_from,date_to,type_to) {
	//if (!type_from) -> get date from date type 
	if (type_from=="now") //get current date
	{
		var date_from = new Date();//new date variable		
		var date_from = date_from.getTime();//get current timestamp
	}
	else if (type_from) //get date from m-d-Y string
	{
		var date_from_year = date_from.substr(6,4);//get year out of date string
		var date_from_day = date_from.substr(0,2);//get day out of date string
		var date_from_month = date_from.substr(3,2);//get month out of date string
		var date_from = new Date();//new date variable
		date_from.setFullYear(date_from_year,date_from_month-1,date_from_day);//set timestamp from date
	}
	//if (!type_to) -> get date to date type 
	if (type_to=="now") //get current date
	{
		var date_to = new Date();//new date variable		
		var date_to = date_to.getTime();//get current timestamp
	}
	else if (type_to) //get date from m-d-Y string
	{
		var date_to_year = date_to.substr(6,4);//get year out of date string
		var date_to_day = date_to.substr(0,2);//get day out of date string
		var date_to_month = date_to.substr(3,2);//get month out of date string
		var date_to = new Date();//new date variable
		date_to.setFullYear(date_to_year,date_to_month-1,date_to_day);//set timestamp to date
	}
	if (date_from && date_to)
	{
		var year_diff = parseFloat((date_to-date_from)/(1000*60*60*24*365));//difference between dates / milliseconds, seconds, minutes, hours, days
		return Math.floor(year_diff);
	}
}


//gets difference of weeks and days from 2 dates

function week_day_diff(date_from,type_from,date_to,type_to) {
	//if (!type_from) -> get date from date type 
	if (type_from=="now") //get current date
	{
		var date_from = new Date();//new date variable		
		var date_from = date_from.getTime();//get current timestamp
	}
	else if (type_from) //get date from m-d-Y string
	{
		var date_from_year = date_from.substr(6,4);//get year out of date string
		var date_from_day = date_from.substr(0,2);//get day out of date string
		var date_from_month = date_from.substr(3,2);//get month out of date string
		var date_from = new Date();//new date variable
		date_from.setFullYear(date_from_year,date_from_month-1,date_from_day);//set timestamp from date
	}
	//if (!type_to) -> get date to date type 
	if (type_to=="now") //get current date
	{
		var date_to = new Date();//new date variable		
		var date_to = date_to.getTime();//get current timestamp
	}
	else if (type_to) //get date from m-d-Y string
	{
		var date_to_year = date_to.substr(6,4);//get year out of date string
		var date_to_day = date_to.substr(0,2);//get day out of date string
		var date_to_month = date_to.substr(3,2);//get month out of date string
		var date_to = new Date();//new date variable
		date_to.setFullYear(date_to_year,date_to_month-1,date_to_day);//set timestamp to date
	}
	if (date_from && date_to)
	{
		var weeks = parseFloat((date_to-date_from)/(1000*60*60*24*7));//difference between dates / milliseconds, seconds, minutes, hours, weeks
		var days = Math.floor((weeks - Math.floor(weeks))*7);
		weeks = Math.floor(weeks);
		return(weeks+"w"+days+"d");
	}
}