Understanding how the 5-digit ZIPCODE product is updated in the United States

Products affected: 5-digit ZIPCODES
The ZIPCODE Data Vendor, "Tom Tom", receives data updates from the United States Post Office (USPS).

Tom Tom updates the ZIPCODE roster quarterly, based on this data received from the USPS.

Since Tom Tom needs to "adjust" the Postal boundary information to align with Road Networks, 
the ZIPCODE roster is approximately 3 months behind the actual Post Office roster of ZIPCODES.
Pitney Bowes then receives quarterly updates from Tom Tom, where Pitney Bowes packages the ZIPCODE data in the various available data formats such as .tab, .SHP, etc. and the data is made available on the Software Data Marketplace for download to purchasers.

The lag between when the USPS releases a ZIPCODE and when that ZIPCODE appears in the shipping product is dynamic, as the schedules of the USPS, the Data Vendor Tom Tom, and Pitney Bowes are all contributing factors to the update process.

Pitney Bowes has no control over the schedules for Tom Tom nor the USPS.

UPDATED:  March 19, 2019