timeAgo.php

<?php
function time_Ago( $time ) {
    // Calculate difference between current
    // time and given timestamp in seconds
    $diff = time() - $time;

    // Time difference in seconds
    $sec = $diff;

    // Convert time difference in minutes
    $min = round( $diff / 60 );

    // Convert time difference in hours
    $hrs = round( $diff / 3600 );

    // Convert time difference in days
    $days = round( $diff / 86400 );

    // Convert time difference in weeks
    $weeks = round( $diff / 604800 );

    // Convert time difference in months
    $mnths = round( $diff / 2600640 );

    // Convert time difference in years
    $yrs = round( $diff / 31207680 );

    // Check for seconds
    if ( $sec <= 60 ) {
        echo "$sec seconds ago";
    }

    // Check for minutes
    else if ( $min <= 60 ) {
        if ( $min == 1 ) {
            echo "one minute ago";
        } else {
            echo "$min minutes ago";
        }
    }

    // Check for hours
    else if ( $hrs <= 24 ) {
        if ( $hrs == 1 ) {
            echo "an hour ago";
        } else {
            echo "$hrs hours ago";
        }
    }

    // Check for days
    else if ( $days <= 7 ) {
        if ( $days == 1 ) {
            echo "Yesterday";
        } else {
            echo "$days days ago";
        }
    }

    // Check for weeks
    else if ( $weeks <= 4.3 ) {
        if ( $weeks == 1 ) {
            echo "a week ago";
        } else {
            echo "$weeks weeks ago";
        }
    }

    // Check for months
    else if ( $mnths <= 12 ) {
        if ( $mnths == 1 ) {
            echo "a month ago";
        } else {
            echo "$mnths months ago";
        }
    }

    // Check for years
    else {
        if ( $yrs == 1 ) {
            echo "one year ago";
        } else {
            echo "$yrs years ago";
        }
    }
}