In a German public construction tender, a bidder’s price is binding for a set period, the Bindefrist. Section 10 of the VOB/A, the tender rules, says the client sets a reasonable period during which bidders are bound to their offers. A period longer than 30 calendar days should be set only in justified cases. Das Ende der Bindefrist ist durch Angabe des Kalendertages zu bezeichnen. The end of the period must be named as a calendar day. During it, the bidder may not withdraw. The duty also runs the other way. The award must reach the bidder before the period ends.