Several deadlines which must be considered in the invention or patenting process are so important that they are referenced several times in this text.

The "One Year Rule" is perhaps the most important. Patent rights will be lost if an application for patent is not filed within one year from the date the invention is first described in a printed publication or placed on sale to the public. Inventors must be diligent in developing their inventions and applying for patents.

The United States is one of the few countries (if not the only country) which generally grants a patent to the first person to conceive of an invention. In most other countries the first person to file an application is granted the patent. It is therefore possible for an inventor to obtain a patent on her invention even though another person files an application on the same invention first. However, the inventor must file her application within one year of the date of the filing of the first application and be able to prove she conceived the invention first. There are other factors which may defeat the second application. For instance, the patent may be denied if the first inventor (second filer) did not use "due diligence" in developing her invention or filing her application.