Human readable interval formatter trait

WithIntervalFormatter.php

<?php 

trait WithIntervalFormatter
{
    private function formatInterval($seconds, $day_lbl = 'd', $hour_lbl = 'h', $minute_lbl = 'm', $second_lbl = 's', $skip_zero = false)
    {
        $secondsInAMinute = 60;
        $secondsInAnHour = 60 * $secondsInAMinute;
        $secondsInADay = 24 * $secondsInAnHour;

        // extract days
        $days = floor($seconds / $secondsInADay);

        // extract hours
        $hourSeconds = $seconds % $secondsInADay;
        $hours = floor($hourSeconds / $secondsInAnHour);

        // extract minutes
        $minuteSeconds = $hourSeconds % $secondsInAnHour;
        $minutes = floor($minuteSeconds / $secondsInAMinute);

        // extract the remaining seconds
        $remainingSeconds = $minuteSeconds % $secondsInAMinute;
        $seconds = ceil($remainingSeconds);

        $ret = [];

        if ($skip_zero) {
            if ($days) {
                $ret[] = $days . $day_lbl;
            }
            if ($hours) {
                $ret[] = $hours . $hour_lbl;
            }
            if ($minutes) {
                $ret[] = $minutes . $minute_lbl;
            }
            if ($seconds || !$ret) {
                $ret[] = $seconds . $second_lbl;
            }
        } else {
            if ($days) {
                $ret[] = $days . $day_lbl;
            }
            if ($hours || $days) {
                $ret[] = $hours . $hour_lbl;
            }
            if ($minutes || $hours || $days) {
                $ret[] = $minutes . $minute_lbl;
            }
            $ret[] = $seconds . $second_lbl;
        }

        return join(' ', $ret);
    }
}