+var tzRe = /^([+-])([0-9][0-9])([0-9][0-9])$/;
+
+/**
+ * convert numeric timezone +/-ZZZZ to offset from UTC in seconds
+ *
+ * @param {String} timezoneInfo: numeric timezone '(+|-)HHMM'
+ * @returns {Number} offset from UTC in seconds for timezone
+ *
+ * @globals tzRe
+ */
+function timezoneOffset(timezoneInfo) {
+ var match = tzRe.exec(timezoneInfo);
+ var tz_sign = (match[1] === '-' ? -1 : +1);
+ var tz_hour = parseInt(match[2],10);
+ var tz_min = parseInt(match[3],10);
+
+ return tz_sign*(((tz_hour*60) + tz_min)*60);
+}