gistfile1.php

<?php
class DistanceOfTimeInWords
{
    const MINUTES_IN_YEAR = 525600;
    const MINUTES_IN_QUARTER_YEAR = 131400;
    const MINUTES_IN_THREE_QUARTERS_YEAR = 394200;

    const UP_TO_24_HOURS = 1440;
    const UP_TO_48_HOURS = 2520;
    const UP_TO_30_DAYS = 43200;
    const UP_TO_60_DAYS = 86400;
    const UP_TO_365_DAYS = 525600;

    /**
     * @var \DateTime
     */
    private $fromTime;
    /**
     * @var \DateTime
     */
    private $toTime;

    public function __construct(\DateTime $fromTime, \DateTime $toTime)
    {
        $this->fromTime = $fromTime;
        $this->toTime = $toTime;
    }

    public function __toString()
    {
        $fromTs = $this->fromTime->getTimestamp();
        $toTs = $this->toTime->getTimestamp();
        
        $distanceInMinutes = round(($toTs - $fromTs) / 60.0);

        if ($distanceInMinutes <= 1) {
            return "less than a minute";
        } elseif ($distanceInMinutes <= 45) {
            return sprintf("%s minutes", $distanceInMinutes);
        } elseif ($distanceInMinutes <= 90) {
            return "about 1 hour";
        } elseif ($distanceInMinutes <= self::UP_TO_24_HOURS) {
            return sprintf("about %s hours", round($distanceInMinutes / 60.0));
        } elseif ($distanceInMinutes <= self::UP_TO_48_HOURS) {
            return "about 1 day";
        } elseif ($distanceInMinutes <= self::UP_TO_30_DAYS) {
            return sprintf("about %s days", round($distanceInMinutes / 1440.0));
        } elseif ($distanceInMinutes <= self::UP_TO_60_DAYS) {
            return sprintf("about %s months", round($distanceInMinutes / 43200.0));
        } elseif ($distanceInMinutes <= self::UP_TO_365_DAYS) {
            return sprintf("%s months", round($distanceInMinutes / 43200.0));
        } else {

            $remainder = $distanceInMinutes % self::MINUTES_IN_YEAR;
            $distanceInYears = floor($distanceInMinutes / self::MINUTES_IN_YEAR);

            if ($remainder < self::MINUTES_IN_QUARTER_YEAR) {
                return sprintf("about %s years", $distanceInYears);
            } elseif ($remainder < self::MINUTES_IN_THREE_QUARTERS_YEAR) {
                return sprintf("over %s years", $distanceInYears);
            } else {
                return sprintf("almost %s years", $distanceInYears + 2);
            }

        }

    }
}