Every such sale shall be at auction for the percentage of the common and undivided interest in the whole property that a bidder is willing to offer for the unpaid tax, interest and costs due thereon. No portion of the property shall be sold in severalty by metes and bounds. The sale shall be held in some public place in town where the land is situate and between the hours of 10:00 a.m. and 6:00 p.m. but, if necessary, the sale may be adjourned from day to day, not exceeding 3 days by proclamation made at the place of the sale within the hours stated in this section.