Zoomed in so fewer days are showing. The color of a task is given by the priority assigned at creation time. The redder the task the higher the priority. The rightmost edge of a task is aligned with the timeline at the bottom according to its deadline.

The length of time it takes to complete a task is denoted by the width of the rectangle. Thus the left edge of a rectangle is the latest possible time the task can be started to complete it by the deadline.

Tasks are sorted by effective priority. Effective priority is calculated by taking into account all the time overlaps with other tasks. The highest effective priority is the one at the top.

By completing the tasks from top to bottom, if there is sufficient time to do all the tasks at all, they will be done optimally to not exceed deadlines. In reality, as work is done for tasks, they will get narrower. That aspect is not simulated here.