The optimal time to book for groups depends on several factors:
The larger your group, the further from travel you will likely need to book if your market (city pairs) has limited flights. Conversely, if you have a smaller group you might have more time to shop the market.
For example, if you were flying from Orlando to New York City with 25 passengers, you can be more patient and check prices. There are many options and three airports that will get you to New York.
However, if you are going from Tampa to Saint Kitts, you may not have the luxury to wait out the very best price, and there are not many flights to the island each day.
On the same note, if you are going into a market during peak travel time, we also recommend getting space as early as possible, as optimizing for the lowest price may not be possible.
Flying to Orlando during Spring Break (March and April), is expensive and many groups compete for space. Book early.
As general guidance, we see the 6-7 month prior to travel as a good blend of ensuring you get the space you need coupled with a group price.