| # Calendar hierarchy This topic describes how calendars are structured. Every calendar can have a parent calendar that provides default data. Therefore, you only need to specify the exceptions to the parent calendar. Additionally, if a planning process queries a calendar for a date that is outside that calendar's date range, LN uses information from the parent calendar. Start defining the calendar structure with the most generic calendar. As you define more specific calendars, in the Calendar Codes (tcccp0110m000) session, in the Parent Calendar field, enter the code of the calendar's parent calendar. You can then use that child calendar as the parent for another calendar, and so on. When you update the calendar, LN displays the full calendar details in the Calendar Working Hours (tcccp0120m000) session, including the details derived from higher-level calendars. In a child calendar, you can add additional working times and mark particular dates as unavailable. To view the calendar hierarchy in a graphical browser, use the Browse Calendars (tcccp0550m100) session. Note Although it is convenient to put the company calendar at the top of the derivation path, you can also select another calendar. Start date and end date A child calendar cannot extend outside the time frame of its parent. Therefore, you cannot set a child calendar's start date earlier than the parent calendar's start date and the child calendar's end date later than the parent calendar's end date. However, you can define a calendar that is only valid for a part of the validity of the parent calendar. If a planning process needs calendar details outside the calendar's date range, LN uses the parent calendar's details. If a calendar has no parent, and planning requires calendar details for a date outside the calendar's validity, LN falls back on the standard calendar. Calendar working times In the Calendar Working Hours (tcccp0120m000) session, you can view the effective calendar details for each date. If the details for a specific date have been derived from a parent or the standard calendar, the Derived From field reads Parent or Standard Calendar. On one date, a calendar can have multiple working times, such as 8:00-12:00 and 13:00-17:00. However, you cannot have multiple time intervals on one date that are derived from disparate sources. For one particular date in a calendar, only one of the following statements can be true: All of the working times are derived from the standard calendar. All of the working times are derived from the parent calendar. All of the working times are derived from a calendar recurrence. The date is unavailable, as specified in the Calendar Non-Available Days (tcccp0119m000) session. All of the working times for that date are manually defined in that calendar. If you try to insert additional working times to a date that already has derived working times, LN gives you the following choices: Copy the derived working hours for that date to the child calendar and set the Derived From field to Manual for these working hours. Delete the derived working hours in the child calendar. Abort the insert operation. Calendar search path If a planning process cannot find the calendar for a particular employee or other resource, LN searches for a calendar defined for the department, enterprise units, and finally the company calendar. Every planning process uses a fixed search path for calendars defined by the LN application. That search path always ends at the company calendar and is independent from the parent calendars you defined. Related topics Overview of calendar functionality To set up the calendar structure To use calendars |