When you look at your cushion, one or more tasks may be below the red zero line. This means you will not have enough time to get them done, as scary as that may be. The point is that you see the problem before it happens, giving you enough time to make adjustments. You may typically see two or three big red spikes, which signal your midterms and finals. Students often try to jam everything into their midterm week, not understanding that there simply isn't enough time during a seven-day period to get four big assignments done.
So let's look at the two ways you can bring your cushion from negative to positive. As an example, I'll use this big paper I have to write. As you can see, it has a negative cushion of 10 hours. When I open it, the first thing I want to do is check how many days before the deadline I set to start working on it. I set six days, so maybe I need to start working on it sooner. Let's see what happens if I start writing 10 days before it's due instead of six. I'll close the window, and my cushion will recalculate, looking whether there is some extra study time during the four additional days that I allocated to this task. Shovel did find some additional study time as my cushion is now only negative four hours, but it's not enough to get the task done on time.
But now let's say I don't want to work on this task any sooner. In that case, I need to look when the task is due, find it in the calendar, and create more study time. Okay, so here's the task, and let's look at where we can create new study time between the start date and the deadline. It looks like there's some "me time" that I can delete from this week to create some new study time. As you can see, when I resize or remove an event, I create more study time to work on the task. Now, when I check my cushion again, I can see I created enough study time to get the task done on time. Now I can relax knowing that my schedule will allow me to get everything done on time. Repeat this process if you have multiple tasks in the red.
If a majority of your tasks are in the red or on the zero line, it can mean two things: You either didn't set start dates on your tasks, or you simply have too much going on and you should consider dropping some of your items from your schedule altogether. The goal here is to create enough study time to get good grades while having enough social time to maintain good mental health.