US PATENT APPLICATION FILING DATES + PATENT EXPIRATION DATES
For Patents issued from nonprovisional applications filed on or after June 8, 1995:
The patent term begins when the patent issues and ends on the date 20 years from the application filing date
Patents issued from continuing applications filed on or after June 8, 1995:
The patent term lasts 20 years from the filing date of the earliest parent (nonprovisional) application.