§ 121.0 Market-dominant product service standards.
Primary source
Verbatim text below is from the Electronic Code of Federal Regulations (eCFR), a public-domain U.S. government work. Always verify the current version with the eCFR before relying on it for any legal matter.
Full Text
Service standards in this part are contingent upon proper acceptance before the applicable day-zero Critical Entry Time (CET). Applying the service standards appearing in this part, effective service standards for combinations of 5-digit originating ZIP Codes and 5-digit destinating ZIP Codes can be found in a lookup table at www.usps.com.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.