Not a pharmacist or giving advice.
My psychiatrist started me off at 20mg of the slow release in January of this year and upped it to 30 a month ago (also slow release).
Is there a reason you are prescribed the 30 and not the 20? To me that makes more sense than expecting you to split a 30mg capsule four ways... Also if you have to spread it out throughout the day you might be better off with a rapid release tablet which can be cut more evenly with a pill cutter.
I found that taking mine as soon as I wake up gives the most beneift as it takes an hour and half before it starts working. Taking it after 09:00 makes me unable to sleep.