Time management is a top capability you need in managing yourself. Half the impression you create as a professional comes from the way you manage time and manage deadlines.
People who manage time well never seem stretched for time and never offer the excuse of being busy. They seem to have the time for many things. When one is a poor time manager, one has to compensate for that with good social skills, so that people are not upset with or angry at you. Poor time management shows an inability to empathize with the other person’s priorities.