Returns date and time in requested format.
formatDateTime(dateStr, format)
dateStr string or number, date in common format
format string, format to output
The str argument can be any standard date or unix epoch, which is used to create JavaScript Date object. The format can contain elements from date and time. This method will call w2utils.formatDate and then w2utils.formatTime methods.
For best cross browser compatibility you should define dateStr either as UNIX time or as full date and time with time zone in the following format: "2013/12/21 19:03:59 PST".