Yes, early entry is always an hour before park opening and is only for IOA. The whole month of July IOA is open from 8am to 10pm. So, early entry will be 7am.
Studios will be open from 9am to 9pm the whole month as well, but no early entry or anything. There is really no reason to make it to this park at opening unless you want to ride Rip Ride Rockit a few times before the line starts to get big since this ride does not have Express access.
Also, if you are not morning people, you can easily see HP in the evening! My favorite way to see HP is when the sun is starting to set. Around 7 or 8 the HP area will really start to calm down giving you about 2-3 hours to see everything. If you are staying for more than 2 or 3 nights, I would skip that very early entry and just hit it at night. With the sun setting around 9pm, you will get around an hour of darkness to see all the nice lighting effects. If you are there three nights, I would do the first and third night at IOA to see HP and the 2nd night at Studios to see the Universal 360 show (assuming you are going after July 4 when the show starts and your Studios day is not on a Sat. when the show will not run due to the Summer Concert Series).