 Canadian restricted hours are similar to critical hours, except that the restriction results from the January 17, 1984, U.S.-Canadian AM Agreement.Canadian restricted hours are called "critical hours" in the U.S.-Canadian Agreement, but in the AM Engineering database, the FCC calls them "Canadian restricted hours" to distinguish them from the domestically defined critical hours.Canadian restricted hours is that time from sunrise to one and one-half hours after sunrise, and from one and one-half hours before sunset until sunset, local time.