Help with date format

hello all, i have a list that has the date like this : 2017-01-12T01:36:02Z
so basically mydate = [2017-01-12T01:36:04Z , 2017-01-12T01:38:06Z , 2017-01-12T01:40:08Z…]

how could i take this and convert it to just
mydate = [01:36, 01:38, 01:40…]
I only want to keep the time. So i want to take the existing list, clean up the rest except hour:time and then save it to the same or another list.
Any help will be appreciated!