103.20—Posting of election notices.
(a)
Employers shall post copies of the Board's official Notice of Election in conspicuous places at least 3 full working days prior to 12:01 a.m. of the day of the election. In elections involving mail ballots, the election shall be deemed to have commenced the day the ballots are deposited by the Regional Office in the mail. In all cases, the notices shall remain posted until the end of the election.
(b)
The term working day shall mean an entire 24-hour period excluding Saturdays, Sundays, and holidays.
(c)
A party shall be estopped from objecting to nonposting of notices if it is responsible for the nonposting. An employer shall be conclusively deemed to have received copies of the election notice for posting unless it notifies the Regional Office at least 5 working days prior to the commencement of the election that it has not received copies of the election notice.
(d)
Failure to post the election notices as required herein shall be grounds for setting aside the election whenever proper and timely objections are filed under the provisions of § 102.69(a).