Setting working times and days off by using Project calendars

Applies to
Microsoft Office Project 2003
Microsoft Project 2002

It's important that your project is completed on time. To accomplish that, you must know when work on project tasks can or cannot be done. Project 2003 and Microsoft Project 2002 use calendars, as well as other information such as task dependencies (task dependencies: A relationship between two linked tasks; linked by a dependency between their finish and start dates. There are four kinds of task dependencies: Finish-to-start [FS], Start-to-start [SS], Finish-to-finish [FF], and Start-to-finish [SF].), to determine when resources are available to work and when tasks can be scheduled.

There are four types of calendars: base calendars, project calendars, resource calendars, and task calendars. You can modify these calendars to define the working days and hours for the entire project, for groups of resources, for individual resources, and for tasks. These calendars are distinct from the Calendar view, which shows the project schedule in a calendar format.

 Note   For more information about modifying calendars, see the related links in the See Also section of this page (visible only when you are connected to the Internet).

What is a base calendar?

What is the project calendar?

What is a resource calendar?

What is a task calendar?

How do calendar option settings affect working times?

How do the project, resource, and task calendars interrelate?

What is a base calendar?

A base calendar defines the usual working and nonworking times (nonworking time: Hours or days designated in a resource or project calendar when Project should not schedule tasks because work is not done. Nonworking time can include lunch breaks, weekends, and holidays, for example.) for the project. It specifies the work hours for each work day, the work days for each week, and also exceptions, such as holidays. You can select any base calendar to use as the project calendar or as the basis for a resource calendar. You can also apply a base calendar to specific tasks.

  • Standard    The Standard base calendar is the default calendar for the project and is the basis for resource calendars. This calendar reflects a traditional work schedule: Monday through Friday, 8:00 A.M. to 5:00 P.M., with an hour off for break.
  • 24 Hours    The 24 Hours base calendar reflects a schedule with no nonworking time at all. The 24 Hours calendar can be used when resources and tasks are scheduled for different shifts around the clock, or when equipment resources work on tasks continuously.
  • Night Shift    The Night Shift base calendar reflects a graveyard shift schedule of Monday night through Saturday morning, 11:00 P.M. to 8:00 A.M., with an hour off for break.

You can also create your own base calendars. Creating your own base calendars is particularly useful if you have alternative schedules for multiple resources. For example, you might have resources working part-time, 12-hour shifts, or on weekends.

 Note   If you use Microsoft Office Project Professional 2003, base calendars are implemented for your organization on Microsoft Office Project Server 2003. Only someone with administrative privileges (for example, your project management administrator) for Project Server 2003 can check out and change base calendars in the enterprise global template.

What is the project calendar?

The project calendar defines the working and nonworking days and times for tasks. This calendar usually represents your organization's traditional working hours. Project uses this calendar to schedule tasks that don't have resources assigned or that have a task type (task type: A characterization of a task based on which aspect of the task is fixed and which aspects are variable. There are three task types: Fixed Units, Fixed Work, and Fixed Duration. The default task type in Project is Fixed Units.) of fixed duration (fixed-duration task: A task in which the duration is a fixed value and any changes to the work or the assigned units [that is, resources] don't affect the task's duration. This is calculated as follows: Duration x Units = Work.). By default, the Standard base calendar is used as the project calendar, but you can reflect alternative schedules by using other base calendars as the project calendar.

Project calendar

Callout 1 The project calendar specifies when project work can occur. In this case, the Project calendar specifies that all days of the week are working days.

Callout 2 In this case, the project calendar defines that work can occur only on weekdays, from 8:00 A.M. to 5:00 P.M.

The working days and hours in the project calendar reflect the working days and hours for your entire project. You can specify special days off, such as company holidays. You can also indicate other nonworking times to reflect periods when the entire team will be working on nonproject activities, such as company meetings or departmental retreats.

What is a resource calendar?

Resource calendars ensure that work resources (people and equipment) are scheduled only when they're available for work. They affect a specific resource or category of resources. By default, the working time settings in the resource calendar match the Standard base calendar. However, you can customize the resource calendar to show individual schedule information, such as vacations, leaves of absence, or equipment maintenance time.

On the Working Time tab of the Resource Information dialog box, you can edit resource calendars to indicate nonworking time. You can also create or assign different base calendars for individual resources or groups of resources to indicate specific working hours. For example, you can assign a resource to a calendar that you created for carpenters who may be working during a time that is different from other workers.

 Note   If you use Project Professional 2003, resource calendars of enterprise resources are secured on Project Server. To make changes to the working and nonworking times of an enterprise resource, you must first check out the resource from Project Server.

When Project schedules the project, it uses the resource calendars to schedule the tasks that do not have a fixed duration and that have resources assigned. For example, if a resource has a week of vacation specified on his or her resource calendar, Project will not schedule the task for that week.

Resource calendar

Callout 1 Initially, each resource's resource calendar settings match those of the Standard base calendar.

Callout 2 After setting a resource's nonworking time, the resource calendar reflects that this resource is not available to do project work this month on the last three days of week one or on the first four days of week two.

If you have alternative schedules that a number of resources work, such as a part-time schedule, a night-shift schedule, or a 24-hour schedule, you can set up and apply a separate base calendar. The base calendar that you create sets the default working time for the project. You can then customize the resource calendars to accommodate exceptions to the individual resource's working times.

If you change working times on a resource calendar and the resource is already assigned to a task, the task is rescheduled during the working times on the resource calendar.

What is a task calendar?

Task calendars make it possible for tasks to occur outside of the project calendar's (or resource calendar's) working time.

The scheduling of tasks is based on the working times established in the project calendar and the resource's associated resource calendar. If a task needs to be completed at a different time — for example, a task that needs to run overnight or through the weekend — you can set up a task calendar.

You create a task calendar in the Change Working Time dialog box as a new base calendar. You then apply the base calendar to a task by choosing options on the Advanced tab in the Task Information dialog box.

If you have applied a task calendar and assigned resources to the task, by default, the task is scheduled for the working times that the task calendar and resource calendars have in common. If you want to schedule the task by using only the task calendar, select the Scheduling ignores resource calendars check box on the Advanced tab in the Task Information dialog box.

How do calendar option settings affect working times?

Calendar option settings on the Calendar tab in the Options dialog box (Tools menu, Options command) define the time settings in Project, but they do not determine when work can be scheduled. These option settings have no effect on the working and nonworking times of calendars. Only calendars can determine working and nonworking times.

On the Calendar tab, you can specify default settings, such as the day each week starts on, the month in which the fiscal year starts, the start time and end time, the total work hours per day, and the number of days per month. For example, the Default start time option specifies the start time that Project assigns to tasks by default when you enter a start date without specifying a time. Additionally, the Hours per day option defines the number of hours that Project calculates for a task when you enter a duration in days, such as the default setting of 8 hours for 1 day. Entering a duration of 2 days would be equivalent to entering a duration of 16 hours.

If you change the working times on a calendar, you need to keep in mind that Project still refers to settings on the Calendar tab to determine the default start and end times and how many hours define a day, week, or month. For example, if the working time in a calendar differs from the Hours per day or Hours per week settings on the Calendar tab, the Duration field may not display the duration value that you expect. You may want to consider matching the calendar settings to the working time on the Calendar tab.

How do the project, resource, and task calendars interrelate?

When you first open a new project file, the Standard base calendar is set as the default project calendar. The Standard base calendar reflects the traditional Monday through Friday, 8:00 A.M. to 5:00 P.M. work week. You can modify the Standard base calendar to match your project's working and nonworking times. You can also apply a different base calendar, such as the Night Shift or 24 Hours calendar, or a base calendar that you created. You can set the project calendar in the Project Information dialog box, available on the Project menu.

The Standard base calendar is also the basis for the default resource calendar applied to each resource in your project. You can also customize the working times for an individual resource's working schedule and vacations. If you apply a different base calendar to resources or customize the working times of an individual resource, the new settings override the project calendar settings when scheduling resources to work on tasks, unless the tasks have a task type of fixed duration.

Any base calendar can be a task calendar. When you create and apply a specific base calendar to a task, its settings override the project calendar settings when scheduling the task. If resources are assigned to the task, the task is scheduled by the working times that the task calendar and resource calendar have in common. You can have the task ignore the settings in the resource calendar by selecting the Scheduling ignores resource calendars check box on the Advanced tab in the Task Information dialog box.