function calendar_strtotime (str, now) {
    // http://kevin.vanzonneveld.net
    // +   original by: Caio Ariede (http://caioariede.com)
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +      input by: David
    // +   improved by: Caio Ariede (http://caioariede.com)
    // +   improved by: Brett Zamir (http://brett-zamir.me)
    // +   bugfixed by: Wagner B. Soares
    // +   bugfixed by: Artur Tchernychev
    // %        note 1: Examples all have a fixed timestamp to prevent tests to fail because of variable time(zones)
    // *     example 1: strtotime('+1 day', 1129633200);
    // *     returns 1: 1129719600
    // *     example 2: strtotime('+1 week 2 days 4 hours 2 seconds', 1129633200);
    // *     returns 2: 1130425202
    // *     example 3: strtotime('last month', 1129633200);
    // *     returns 3: 1127041200
    // *     example 4: strtotime('2009-05-04 08:30:00');
    // *     returns 4: 1241418600
    var i, l, match, s, parse = '';

    str = str.replace(/\s{2,}|^\s|\s$/g, ' '); // unecessary spaces
    str = str.replace(/[\t\r\n]/g, ''); // unecessary chars
    if (str === 'now') {
        return now === null || isNaN(now) ? new Date().getTime() / 1000 | 0 : now | 0;
    } else if (!isNaN(parse = Date.parse(str))) {
        return parse / 1000 | 0;
    } else if (now) {
        now = new Date(now * 1000); // Accept PHP-style seconds
    } else {
        now = new Date();
    }

    str = str.toLowerCase();

    var __is = {
        day: {
            'sun': 0,
            'mon': 1,
            'tue': 2,
            'wed': 3,
            'thu': 4,
            'fri': 5,
            'sat': 6
        },
        mon: [
            'jan',
            'feb',
            'mar',
            'apr',
            'may',
            'jun',
            'jul',
            'aug',
            'sep',
            'oct',
            'nov',
            'dec'
        ]
    };

    var process = function (m) {
        var ago = (m[2] && m[2] === 'ago');
        var num = (num = m[0] === 'last' ? -1 : 1) * (ago ? -1 : 1);

        switch (m[0]) {
        case 'last':
        case 'next':
            switch (m[1].substring(0, 3)) {
            case 'yea':
                now.setFullYear(now.getFullYear() + num);
                break;
            case 'mon':
                now.setMonth(now.getMonth() + num);
                break;
            case 'wee':
                now.setDate(now.getDate() + (num * 7));
                break;
            case 'day':
                now.setDate(now.getDate() + num);
                break;
            case 'hou':
                now.setHours(now.getHours() + num);
                break;
            case 'min':
                now.setMinutes(now.getMinutes() + num);
                break;
            case 'sec':
                now.setSeconds(now.getSeconds() + num);
                break;
            default:
                var day = __is.day[m[1].substring(0, 3)];
                if (typeof day !== 'undefined') {
                    var diff = day - now.getDay();
                    if (diff === 0) {
                        diff = 7 * num;
                    } else if (diff > 0) {
                        if (m[0] === 'last') {
                            diff -= 7;
                        }
                    } else {
                        if (m[0] === 'next') {
                            diff += 7;
                        }
                    }
                    now.setDate(now.getDate() + diff);
                }
            }
            break;

        default:
            if (/\d+/.test(m[0])) {
                num *= parseInt(m[0], 10);

                switch (m[1].substring(0, 3)) {
                case 'yea':
                    now.setFullYear(now.getFullYear() + num);
                    break;
                case 'mon':
                    now.setMonth(now.getMonth() + num);
                    break;
                case 'wee':
                    now.setDate(now.getDate() + (num * 7));
                    break;
                case 'day':
                    now.setDate(now.getDate() + num);
                    break;
                case 'hou':
                    now.setHours(now.getHours() + num);
                    break;
                case 'min':
                    now.setMinutes(now.getMinutes() + num);
                    break;
                case 'sec':
                    now.setSeconds(now.getSeconds() + num);
                    break;
                }
            } else {
                return false;
            }
            break;
        }
        return true;
    };

    match = str.match(/^(\d{2,4}-\d{2}-\d{2})(?:\s(\d{1,2}:\d{2}(:\d{2})?)?(?:\.(\d+))?)?$/);
    if (match !== null) {
        if (!match[2]) {
            match[2] = '00:00:00';
        } else if (!match[3]) {
            match[2] += ':00';
        }

        s = match[1].split(/-/g);

        s[1] = __is.mon[s[1] - 1] || s[1];
        s[0] = +s[0];

        s[0] = (s[0] >= 0 && s[0] <= 69) ? '20' + (s[0] < 10 ? '0' + s[0] : s[0] + '') : (s[0] >= 70 && s[0] <= 99) ? '19' + s[0] : s[0] + '';
        return parseInt(this.strtotime(s[2] + ' ' + s[1] + ' ' + s[0] + ' ' + match[2]) + (match[4] ? match[4] / 1000 : ''), 10);
    }

    var regex = '([+-]?\\d+\\s' + '(years?|months?|weeks?|days?|hours?|min|minutes?|sec|seconds?' + '|sun\\.?|sunday|mon\\.?|monday|tue\\.?|tuesday|wed\\.?|wednesday' + '|thu\\.?|thursday|fri\\.?|friday|sat\\.?|saturday)' + '|(last|next)\\s' + '(years?|months?|weeks?|days?|hours?|min|minutes?|sec|seconds?' + '|sun\\.?|sunday|mon\\.?|monday|tue\\.?|tuesday|wed\\.?|wednesday' + '|thu\\.?|thursday|fri\\.?|friday|sat\\.?|saturday))' + '(\\sago)?';

    match = str.match(new RegExp(regex, 'gi')); // Brett: seems should be case insensitive per docs, so added 'i'
    if (match === null) {
        return false;
    }

    for (i = 0, l = match.length; i < l; i++) {
        if (!process(match[i].split(' '))) {
            return false;
        }
    }

    return now.getTime() / 1000 | 0;
}