This column governs the length of time (in minutes) associated with the product and is used in conjunction with the ramp rates in the Resources table.
For example, in the table below the first row indicates that resources assigned the Spin product ID need enough capacity as a group such that in 10 minutes the resources can increase their generation by 30 MW. This is directly related to the ramp rate. So if a 100 MW resource with a ramp rate of 50% per hour was part of the Spin product, then it would be able to provide at a maximum 100*.50*10/60 = 8.33 MW of reserves to this product.
Time Length Column