A more thorough explanation:

In the field of patents, the bar date refers to the deadline by which a patent application must be filed to avoid losing the right to receive a patent.

In the United States, the bar date for a patent application is one year after the invention is disclosed in a publication or patented in another country, or put into public use, sold, or offered for sale in the U.S.

For example, if an invention was offered for domestic sale on January 1, 2020, the bar date for the U.S. patent application would be January 1, 2021.

It is important to meet the bar date to protect the inventor's rights to the invention and prevent others from using or profiting from it without permission.