Some organizations do not have strict regulations around notice periods, and for others, it is imperative to know about absences far in advance for planning or scheduling purposes. Some types of leave may require advanced notice, such as vacations. Others may be taken without much or any notice, such as sick leave. As with most policies, it is advisable to codify these requirements so that expectations are clear and employees understand their options. When designing your policy, consider the needs of your business's scheduling and coverage needs. If expectations and regulations are not specifically written down, norms will be decided by the unspoken aspects of your culture and may not be regulated enough to support the requirements of the business.