adafruit coupon days between

gistfile1.txt

var dates = [
	"2017-01-11",
	"2017-01-04",
	"2016-12-21",
	"2016-12-07",
	"2016-11-03",
	"2016-10-27",
	"2016-10-13",
	"2016-09-22",
	"2016-09-15",
	"2016-08-25",
	"2016-08-18",
	"2016-08-11",
	"2016-08-04",
	"2016-07-21",
	"2016-07-07",
	"2016-06-23",
	"2016-06-09",
	"2016-06-02",
];

function daysBetween( date1, date2 ) {
	var day_millis = ( 1000 * 60 * 60 * 24 );
	var parts = date1.split( "-" );
	var firstDate = new Date( parts[0], parts[1], parts[2] );
	var parts = date2.split( "-" );
	var secondDate = new Date( parts[0], parts[1], parts[2] );
	return Math.round( Math.abs( ( firstDate.getTime() - secondDate.getTime() ) / day_millis ) );
}

var avg = 0;
for ( var i = 0; i < dates.length; i++ ) {
	
	if ( i === 0 )
		continue;

	var days = daysBetween( dates[ i ], dates[ i - 1 ] );
	avg += days;
	console.log( days );

}

console.log( "Average: "+ Math.round( avg / dates.length ) );