Usually you can find this information on the
Extra Magic Hour FAQ page. Clearly something is amiss because the grid calendar has been updated for October, but the FAQ hasn't. In order to figure out which Extra Magic days are morning or evening, you can use past history as a guide. For example if you look at the Extra Magic FAQ, you'll see that the Magic Kingdom has
morning Extra Magic time on the 4th, 11th, 18th, and 25th of September. These are all Thursdays. On the
grid calendar you will see Extra Magic time listed for every Thursday in October. So, it's probably a fairly good guess that these are morning hours as well.
I'm sure they'll update the FAQ link soon, but until then, you can mostly figure it out on your own.
Hope this helps.