What's in a name?
File Naming: The file naming convention is as follows: ssssdddh.zip. Where “ssss” is used to identify the site name, “ddd” is the day of the year, “h” is the hour identifier (UT), and .zip is the type of compression used. The files are organized in directories according to the year, day of year, site and UT hour of day.
Do not be confused by the times listed on the left of the Rinex data page. They are the times the files were posted from the sites. The 8th character in the file name indicates the data range: "a" 0:00 UT - 0:59 UT , "b" 1:00 UT - 1:59 UT, ..., "x" 23:00 UT - 23:59 UT.
1 AM
6 PM
5 PM
2 AM
7 PM
3 AM
8 PM
4 AM
9 PM
5 AM
10 PM
6 AM
11 PM
7 AM
12 PM
8 AM
9 AM
10 AM
11 AM
12 PM (noon)
1 PM
2 PM
3 PM
4 PM
12 AM (noon)