In a business, employees aren't expected simply to remember the gadzillion of specific things they have to do as specific times. No, they write all that stuff down. You can too. Think of it as a way to de-clutter your mind. Attack difficult things when you are most mentally sharp.
Some people are morning people and some are afternoon people.
Make them specific. Be aware of your time limitations. Allow a time cushion. Don't cram every minute with activities. Provide for the unexpected.