The personal representative, should he or she deem it for the best interests of all concerned, may postpone such sale to a time fixed but not to exceed twenty days, and such postponement shall be made by proclamation of the personal representative at the time and place first appointed for the sale; if there be an adjournment of such sale for more than three days, then it shall be the duty of the personal representative to cause a notice of such adjournment to be published in a legal newspaper in the county in which notice was published as provided in RCW 11.56.060, in addition to making such proclamation.