There are many reasons you may need to stay home from work. For example, you may get sick, need to attend to personal errands that can't be taken care of on the weekend, go to doctor's appointments, or attend a function at your child's school.
Some employers allot their employees a certain amount of paid sick, vacation, and personal leave days per calendar year. They may also offer some paid holidays. However, with only a certain number of days off per year, it can be difficult to determine, how, when, and under what circumstances these days should be used.
Some employers simply allot leave days—employees can determine how and when they are used.