Create a javascript function that finds available time slots from an array of event dates.

I have a function that returns an array of events which contain start times and end times, and I also have variables set as constraints (minimum start time, maximum end time). You need to write a simple function that will iterate through each item in the array, and return the first available (no overlapping events) start time for a specific duration which is within the specified constrained start and end times.) Very simple function, basic loop with calculation of amount of time between each events start and end times to get available gaps, then see if gaps are big enough for the specified duration, once it finds the earliest gap that fits, it returns the first available start datetime.