No 58 is the best.
As soon as you enter the date and time, The Ds will turn off. Now turn it on and wait for the second's hand to hit 57 and then enter the game and immediatly talk to terrakion check it's nature and Ivs. Also if you get the wrong nature save once before talking to Terrakion. If that doesen't work save twice etc.....
Make sure munna is in the front.