actually it looks like it wants unix time (note that it's *milliseconds* instead of seconds):
from java.util Class Date:
long now = new Date().getTime();
and it looks like the parameters you want for the request are "s" and "e" (for start and end):
Returns the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by this Date object.
String acctName = req.getParameter("acct");
String startStr = req.getParameter("s");
String endStr = req.getParameter("e");