Notaries often are asked to certify that certain events or actions have occurred. The problem is, unless you live in the state of Washington, U.S. Notaries are not permitted to certify events themselves.
However, if you are a Washington Notary, you may certify that an event has occurred or an act has been performed. Such certification is based on either the Notary's personal knowledge or on the oath or affirmation of a credible witness.
Outside Washington state, you may execute a jurat for a signer who attended the event and is signing a sworn written statement that it took place.