DateService.php

DateService.php

<?php

class DateService
{

    /**
     * Return number of day in the week in an European manner, 
     * 0 is Monday, 6 is Sunday
     * @param $unixTimestamp integer
     * @return integer
     */
    public function getDayOfWeekNumber($unixTimestamp)
    {
        return date('N', $unixTimestamp) - 1;
    }

    /**
     * This important since int he DB there is: year, week, day_of_week. 
     * To turn those into a unix timestamp use this function.
     * @param $weekdayNumber integer 0 for Monday, 6 for Sunday
     * @param $week integer number of the week
     * @param $year integer number of the year
     * @return integer unix timestamp
     */
    public function weekdaynumberWeekAndYearToTimestamp($weekdayNumber, $week, $year)
    {
        $weekStartTime = $this->getWeekStartTimestamp($year, $week);
        return $this->addDays($weekStartTime, $weekdayNumber);
    }

    /**
     * @param $year integer number of the year
     * @param $week integer number of the week
     * @return integer unix timestamp
     */
    public function getWeekStartTimestamp($year, $week)
    {
        $week = str_pad($week, 2, '0', STR_PAD_LEFT);
        return strtotime($year . 'W' . $week);
    }

    /**
     * @param $timestamp
     * @param $days
     * @return integer unix timestamp
     */
    public function addDaysToTimestamp($timestamp, $days)
    {
        return $timestamp + 24 * 60 * 60 * $days;
    }

}