For good cause, the officer may postpone such sale for a time not exceeding seven days, and so from time to time until it is completed, giving notice of such adjournment by public proclamation at the time and place appointed for the sale. Such real estate, or an undivided fractional part thereof sufficient to satisfy the execution with costs, shall be sold, and if, in the opinion of the officer, it is divisible, shall be sold in separate tracts and parcels.