No Title
Chutney. there is no special significance to the \'5\'. it is just a digit used to identify the numbering system. In fact, almost all the cases filed at service centers will have a 5 (including H1B petitions). Also, the number of days part identifies the number of working days where 001 would be the first working day in the month of oct and 030 would probably be sometime in november.
I think immigration-law.com has the complete explanation in one of their archives.