IMO , you shouldn’t go crazy about a specific time managment/schedule, as in the end, thinking and thinking about what, when and how you’re going to do something, will consume even more time.
However, in my case for instance, when I know I am going to have a busy day (which envolves several hours of work and which can but is not limited to doing tasks that have a flexible time-requirement) I tend to lay out a ‘first, second, third and finally’ day. Additionally, I try to press beneath my skull what goal I want to achieve (for a specific day/week/etc.), and if that’s not done, what should be the secondary goal to follow-up.
In short, don’t think too much about timing, yet try to have a simple DO FIRST AND DO SECOND structure with a ACHIEVE THIS AND THAT result (specially for those busy, nasty days).