When did nuns change their style of habit?

When they take a bath. that"s about it. they do not normally operate under cover or in plain clothes, like detective cops such as Dragnet men. The motion picture ( A change of Habit) was highly innacurate. No nuns, and especially not novices would be permitted an Undercover or plainclothes assignment-in the film they were nurses in a hospital- some or all romancing Doctor Presley ( of all people) Nobody would normally assign novices to such an assignment- anymore than than one would use a private out of BT for a highly sensitive spy mission! Nuns don"t operate undercover- normally, but some religious orders have relaxed the uniform code somewhat. In some cases the modern habit suggests the occupational garb of, well, a female subway conductor- though she would not have a veil. so it goes.