1)
private SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd_HHmmss"); // or whatever format you prefer
sdf.setTimeZone(TimeZone.getTimeZone("GMT"));
sdf.format(new Date()) will now generate the date string in GMT timezone.
2)
ticks don't have volume, only bars. So you have to extend the onBar() function, and call the corresponding bidBar.getVolume() or askBar.getVolume().
I suggest to post Automated Trading related posts in the proper section (Automated Trading->Knowledgebase). This topic has nothing to do with Strategy Contest (or not directly). There you have better chances of getting replies in such manners...