Assuming that the entire workout is for one muscle system (pushing, pulling, legs), would there be negative effects if I perform one part of the workout in the morning, for example, and the rest of it at night? Thank you.
In my experience, splitting your workout into 2 parts actually gives you a more intense and detailed experience. Let's say I have a push workout scheduled for a certain day. Going in the morning when i'm sluggish and on a time constraint about work/school/meals etc., I can get a quick cardio/abs session in (up to you, cardio in the morning is a great way to start out) along with possibly a solid 3 sets of overhead press and another 4 of bench press within an hour. Keeping it under an hour allows me to train hard and intense with little time for rest. Later in the day or towards the end, I can come back and hit the other workouts without worrying about gym traffic for the bench or squat rack to do overhead presses. I can do some high rep work with machines/dumbbells. Again, giving yourself an hour keeps it intense and low on breaks.
At the end of the day, it's about tearing your muscle fibers and repairing them. Shorter workouts allow you to up the intensity. Just remember what you do outside of the gym has more of an impact than the timing of your workouts, so keep up a solid nutrition regimen.