code: function() {
              var items = this.initItems('d'), name, i,
                  twoDigit = this.options.template.indexOf('DD') !== -1;
                  
              for(i=1; i<=31; i++) {
                  name = twoDigit ? this.leadZero(i) : i;
                  items.push([i, name]);
              }
              return items;        
          }
docs: /*
  fill day