strtoseconds.php

<?php


/**
 * Get time in seconds from user entered interval
 *
 * @param $time
 * @return int seconds
 */
function strToSeconds($time)
{
  // seconds pass through
  if (preg_match('/^\d+$/', trim("$time"))) {
    return intval($time);
  }

  $time = preg_replace('/(\s*|,|and)/i', '', $time);
  $pieces = preg_split('/(?<=[a-z])(?=\d)/i', $time, 0, PREG_SPLIT_NO_EMPTY);
  return array_sum(array_map('strToSeconds_do', $pieces));
}

/** @noinspection PhpUnusedPrivateMethodInspection */
function strToSeconds_do($time)
{
  if (preg_match('/^(\d+)\s*(s|secs?|seconds?)$/', $time, $m)) {
    return intval($m[1]);
  }

  if (preg_match('/^(\d+)\s*(m|mins?|minutes?)$/', $time, $m)) {
    return intval($m[1]) * 60;
  }

  if (preg_match('/^(\d+)\s*(h|hours?)$/', $time, $m)) {
    return intval($m[1]) * 60*60;
  }

  if (preg_match('/^(\d+)\s*(d|days?)$/', $time, $m)) {
    return intval($m[1]) * 86400;
  }

  if (preg_match('/^(\d+)\s*(w|weeks?)$/', $time, $m)) {
    return intval($m[1]) * 86400*7;
  }

  if (preg_match('/^(\d+)\s*(M|months?)$/', $time, $m)) {
    return intval($m[1]) * 86400*30;
  }

  if (preg_match('/^(\d+)\s*(y|years?)$/', $time, $m)) {
    return intval($m[1]) * 86400*365;
  }

  throw new Exception("Bad time interval: \"$time\"");
}