DateFormat class for Laravel (or anyone)

DateFormat.php

<?php


class DateFormat {


	const DATE_SHORT = 'Y-m-d';
	const DATE_LONG = 'F j, Y';
	const DATETIME_SHORT = 'Y-m-d H:i';
	const DATETIME_LONG = 'F j, Y, g:i a';


	public static function now() {
		return new DateTime('now');
	}

	public static function convert($string) {
		if ($string instanceof DateTime) return $string;
		return new DateTime($string);
	}

	public static function interval($date1, $date2='now') {
		$date1 = static::convert($date1);
		$date2 = static::convert($date2);
		return $date1->diff($date2);
	}


	public static function nice_interval($date1, $date2='now') {
		$interval = static::interval($date1,$date2);

		$when = $interval->invert ? 'from now' : 'ago';
		$days = intval( $interval->format('%a') );


		if ($interval->m > 18) {
			$num = $interval->y;
			$units = 'year';
		} else if ($days > 45 ) {
			$num = $interval->m;
			$units = 'month';
		} else if ($days > 10) {
			$num = round($days/7);
			$units = 'week';
		} else if ($days > 1) {
			$num = $days;
			$units = 'day';
		} else if ($days || $interval->h) {
			$num = $interval->h + (24*$days);
			$units = 'hour';
		} else if ($interval->i) {
			$num = $interval->i;
			$units = 'minute';
		} else {
			return sprintf('moments %s', $when);
		}

		return sprintf('%d %s %s',
			$num,
			Str::plural($units, $num),
			$when
		);

	}


}