For some reason, the dates jump on Monday, and do not remain in their places. 
The following settings are set:
showOn:"focus", showAnim:"fadeIn", showOptions:{}, defaultDate:null, appendText:"", buttonText:"...", buttonImage:"", buttonImageOnly:!1, hideIfNoPrevNext:!1, navigationAsDateFormat:!1, gotoCurrent:false, changeMonth:!1, changeYear:!1, yearRange:"c-10:c+10", showOtherMonths:!1, selectOtherMonths:!1, showWeek:!1, calculateWeek:this.iso8601Week, shortYearCutoff:"+10", minDate:+1, maxDate:null, duration:"fast", beforeShowDay:null, beforeShow:null, onSelect:null, onChangeMonthYear:null, onClose:null, numberOfMonths:1, showCurrentAtPos:0, stepMonths:1, stepBigMonths:12, altField:"", altFormat:"", constrainInput:!0, showButtonPanel:!1, autoSize:!1, disabled:!1