Lesson 2: Calendars

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An important aspect in project planning is to add holidays as non-working days and time-off periods for the resources involved in your project. Having a task complete on Christmas day is never likely to be a realistic expectation! Holidays, vacations, medical leave. People take time off. And keeping track of non-working time is critical for making sure your project meets its deadline. To make sure you never get caught out you can add holidays (non-working time) to the project calendar.

Calendars are used in Project Plan 365 to schedule your project and to identify working times to determine when resources in your organization are likely available to work on tasks in your project. Typically, calendars are assigned to resources so that the application can track when resources are available to work on tasks to which they are assigned. Take into account that you need to set up calendars for your project before you can assign them to resources. By default, tasks are scheduled based on the project calendar. To define unique or specific exceptions for working time and non-working time, you can create a task calendar.

There are four types of calendars:

  • Base calendars: Project Plan 365 uses base calendars as a starting point for creating the other three types of calendars (project, task, and resource calendars). You can think of them as templates upon which other calendars are based.

  • Project calendars: The project calendar sets the default working times for all tasks in your project. For example, if most of the work on your project happens between 8 a.m. and 5 p.m. Monday through Friday, the out-of-the-box Standard calendar is the best choice for your project calendar. When you set the project calendar you are simply choosing what the default working times will be for tasks and resources in your project. You can modify working times for individual tasks and resources to reflect exceptions to the default hours.

  • Resource calendars: Use resource calendars to track the schedules of individual resources. Resource calendars make sure that work resources (people and equipment) are scheduled only when they're available for work. For example, if a resource has a flexible work arrangement and works four 10-hour days instead of five 8-hour days, you can set that resource's calendar to reflect that schedule without changing the overall schedule for all other resources in the organization. By default, the working time settings in the resource calendar match the project calendar. However, you can customize the resource calendar to show individual schedule information, such as vacations, leaves of absence, or equipment maintenance time.

  • Task calendars: Task calendars are not often used, but they can be very powerful. Use task calendars to enter special days specific to individual tasks in your project. For example, if the task must happen over a weekend but your project calendar specifies weekends as non-working time, you can use a task calendar to call out that weekend as working time for just that task while leaving the rest of the project using the normal project calendar.

When setting up your project's calendar, you need to decide which base calendar you want to use as a starting point. If most of your tasks need to be completed during normal working hours, choose the Standard base calendar. If most of your tasks need to be completed during off hours, the Night Shift base calendar may make more sense for your project. Or, if your project needs continuous coverage, choose the 24 Hours base calendar.

The Standard calendar is the default base calendar. The base calendar is applied to all resources as you add them. You can assign a different base calendar to the resource, or you can modify the individual's resource calendar. By default, the Standard base calendar is used as the project calendar.

Tasks can have their own calendars. By default, tasks are scheduled based upon the project calendar. To define unique or specific exceptions, such as for machinery that runs during non-working time, or an office move that can occur only on a weekend, you can create a task calendar for individual tasks. A task calendar that is associated with a task overrides the project calendar.

To add holidays in your project, use the current project calendar. It has the words (Project Calendar) after its name. To add vacation days in your project, use the person's resource calendar. It has the same name as that person. Project Plan 365 reschedules tasks around the new non-working time.

Project calendars and task calendars are used to schedule tasks, and if resources are assigned to tasks, resource calendars are used as well. You can modify these calendars to define the working days and hours for the whole project, for individual resources, and for tasks.

Note: When trying to develop a meaningful and realistic project schedule, keep in mind the following aspects:

  • Avoid modifying the standard calendars: keep the default settings for the standard, 24-hour, and night-shift calendars. If you need to change any of the calendars from their default settings copy the calendar of choice to a new calendar which you can use as the basis for your project

  • Unless you have a specific need to say a task finishes at a particular hour within a particular day, try to keep to an hours-per-day setting for your project calendar.

  • Do make sure you record non-working times for resources - Record things like vacation time and times out of office.

  • Be careful with creating too many task exceptions: if you truly have some task-level exception where you need to use a customized calendar then by all means do so, but beware that too many exceptions could make maintenance of your project a real pain.

icon_exercises.png           Practice

   1. Check the type of base calendar that is used as starting point for the project calendar. To achieve this, go to File → Options menu and point to the Project Info tab → Calendar section. You will found out that the Standard calendar is used as the base for the project calendar.​

Let's add holidays in the project, applicable to all tasks and resources. We will add them as exceptions to the project calendar. To this end, click on Project → Change Working Time option. In the For calendar drop-down list select Standard (Project Calendar) entry. In the Exceptions tab enter Christmas and New Year as holidays, during which no work will take place. Enter the name of the holiday in the cell from the Name column. In the Start and Finish columns enter the start and end dates of the current holiday.

Notice in the displayed calendar from the Change Working Time dialog that now 24 December is indicated as a non-working day.

    3. To take into account also the availability of your resources that are working in your project, let's introduce a time-off period for one of the resources. More exactly, we will add a time-off period during Thanksgiving for the resource called G.C. General Management. For this, we will use the calendar of the G.C. General Management resource and we will edit it by adding exceptions to the normal working time. To do this, open again the Change Working Time dialog and from the list select the calendar for G.C. General Management resource. In the Exceptions tab, enter Thanksgiving time-off as the name of the exception and specify the start and end date for the time-off period.


Notice that also in this case, in the calendar displayed in the Change Working Time dialog, 26 and 27 November are marked as non-working days in the resource's calendar.

   4. Now let's suppose that during the summer period, some of the tasks in your project may also take place during the weekend, since we have more daylight during summer. For this we will edit the calendar of Drywall Contractor resource and indicate Saturday as working day. For this open Change Working Time dialog and from the list select the calendar for Drywall Contractor. In the Exceptions tab, add an exception called Weekend that takes place between 6 May 2016 and 8 June 2016. Select this exception by clicking on its name and click on Details... button.


In the opened Exception Details dialog, check the Working times radio-button, under the Recurrence pattern select Weekly and check the boxes corresponding to all the week days, excepting Sunday, therefore indicating that Saturday is also a working day. Press OK button.
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