Hi @Lisa8912
I don't think the New Listing "Boost" lasts that long (3 months). Airbnb automatically gives you the boost in search results as a new listing as @Mike-And-Jane0 said.
I believe you can turn the 20% New Listing Discount back on by going to your calendar/pricing, scroll to the bottom and look for "new listing promotion". I would be careful not to leave your calendar open as far out as you have it though, as someone can book at that 20% discount during your busy season, holidays, etc. Your goal is to give the 20% discount for the first 3 bookings quickly. If you keep your calendar open for say 1yr, then all bets are off and any savvy guest can use that 20% discount for any date open like Memorial Day, 4th July, Labor Day, Christmas, New Years, etc. (you get the idea).
I usually suggest New Hosts turn off the 20% Airbnb New Listing promotion and manually discount their prices only on the dates they want. This prevents someone from booking a holiday at 20% off. I also advise they only open the calendar for a approx 3wks-1month or so until they get the 1st 3 bookings. After that 3rd review, you'll get your review stars to appear on the thumbnail photo. Then change your prices according to your competion after you get those 1st 3 bookings and open up the calendar as you like.
