Interval Parser - from "English" to "Seconds"

DurationParser.js

function parseInterval(interval){
            var u = {};
            u["minute"] = 1;
            u["hour"] = 60 * u["minute"];
            u["day"] = 24 * u["hour"];
            u["week"] = 7 * u["day"];
            u["month"] = 30 * u["day"];
            u["quarter"] = 3 * u["month"];
            u["year"] = 365 * u["day"];
            
            var numbers = interval.match(/[0-9]+/g);
            var words = interval.split(/[0-9]+/g);
            var result = 0;
            for (var i = 1; i < words.length; i++) {
                for (unit in u) {
                    if (words[i].indexOf(unit) !== -1) {
                        var num = parseInt(numbers[i - 1], 10) * u[unit];
                        if (!isNaN(num)) {
                            result += num;
                        }
                    }
                }
            }
            if (result == 0) {
                result = parseInt(interval, 10);
            }
            return isNaN(result) ? 0 : result;
        }