29 CFR 1912.27: Notice of meetings.

Public notice of any meeting of an advisory committee shall be given by the officer or employee calling the meeting at least fifteen (15) days in advance of the meeting; except when it is impractical to do so, or in an emergency situation, in which event shorter advance notice may be given to the extent that any advance notice is practical. It shall, however, be a general policy to publish notices as far in advance of the meeting as circumstances will permit. Such notice shall be given by publication in the Federal Register. In addition, notice may be given by such other means as press releases.