The lookback period (number of days) is set at 21,13,11,8 and 5 days. A heat-map is generated for each of these lookback periods, the best trade from day is scored.
The period of time that has consistently produced the best results becomes the hotspot for that lookback period. There are also different look-back types like Taylor and Taylor Plus.
Taylor cycles are usually 3-day cycles. A Taylor-5 look-back would use the last 5 trading days skipping back by 3 trading days.
Taylor Plus uses calendar days so weekends and non-trading days are counted as part of the skip count. If a lookback period falls on a none trading day, it is not used so a TaylorPlus will continue skipping back until 5 trading days are found for the heatmap calculation.