(a) Invitations for bids for construction shall allow sufficient time for bid preparation (i.e., the period of time between the date invitations are distributed and the date set for opening of bids) (but see 5.203 and 14.202-1) to allow bidders an adequate opportunity to prepare and submit their bids, giving due regard to the construction season and the time necessary for bidders to inspect the site, obtain subcontract bids, examine data concerning the work, and prepare estimates based on plans and specifications.