Each set of subscriber files will be posted 28 days prior to the effective date. The files
will contain data that is updated for that 28 day cycle and has met the cutoff for entry.
By FAA policy and order, many NASR resources, generally categorized as "Enroute," are still updated
on a 56 day charting basis. The following files will be included in the 28 day subscriber set, but will only change every
56 days: ATS, AWY, PFR, ARB, CDR, MTR, SSD, PJA, and STARDP, and WXL.