In most foreign countries, including the European Union, public disclosure of your invention before you file a patent application will result in you not being able to get a patent. Canadian being a notable exception. Canada has a one year grace period similar to the U.S.
In addition, if you wish to obtain foreign patents, you must:
- either file your foreign patent applications within a year of filing your U.S. patent application or provisional application; or
- file a PCT application within one year of filing your U.S. patent application or provisional application. A PCT application can give you eighteen additional months to file your foreign applications.