if (!this.built || force || date.getFullYear() !== viewDate.year || date.getMonth() !== viewDate.month) {
              angular.extend(viewDate, {year: picker.$date.getFullYear(), month: picker.$date.getMonth(), date: picker.$date.getDate()});
              picker.$build();
            } else if (date.getDate() !== viewDate.date || date.getDate() === 1) {
                // chaging picker current month will cause viewDate.date to be set to first day of the month,