code: function (date, type) {
              var time = date.getTime(),
                  d = datepicker.getParsedDate(date),
                  min = datepicker.getParsedDate(this.minDate),
                  max = datepicker.getParsedDate(this.maxDate),
                  dMinTime = new Date(d.year, d.month, min.date).getTime(),
                  dMaxTime = new Date(d.year, d.month, max.date).getTime(),
                  types = {
                      day: time >= this.minTime && time <= this.maxTime,
                      month: dMinTime >= this.minTime && dMaxTime <= this.maxTime,
                      year: d.year >= min.year && d.year <= max.year
                  };
              return type ? types[type] : types.day
          }
docs: Check if date is between minDate and maxDate
  @param date {object} - date object
  @param type {string} - cell type
  @returns {boolean}
  @private