[pbnjay]

How granular are the durations? If days for example you could bucket into N-week intervals (eg intervals with 7N consecutive days) to reduce the search scope. Then you only need to store start times, and can join or use a set to combine other ranges with the same availability.

[grovesNL]

The duration granularity is days right now, but the total duration of the map might extend out for tens of years or so. I did try bucketing them into hundreds of day long intervals but it didn't seem to help very much.