@Stephanie1933 You don't use promotions to get bookings. You use them to get eyes and click-throughs on your listing, which raises you in rankings, which results in non-discounted bookings.
Those unbooked days a few weeks away should remain priced consistent with what other guests have paid. Changing your listing description so your place goes up in search results as recently updated will get you more views and those dates will probably get booked.