In project management, calendars determine when work can occur. In Microsoft Project, calendars define the working and non-working time for the schedule. You can create a variety of calendars within the program for different projects. You can even use multiple calendars within one single project for different types of tasks. Microsoft Project allows you to create a variety of calendars to show exactly when work will be performed and when it will not.

While Microsoft Project will provide several default calendars for use, you may need to create your own as well. You should create your desired calendar before adding tasks to the project. However, this is not imperative – you can always adjust the assigned project, task and resource calendars later on as needed.

This article will demonstrate how to create, edit, and assign calendars within Microsoft Project. The following examples are from Microsoft Project 2021 Professional. However, the process is the same for most versions of Project.

Types of Calendars Available in Microsoft Project

There are four types of calendars within Project: base, project, task, and resource.

Base Calendars

Base calendars are generally default template calendars. By default, Project will provide three base calendars: Standard, 24 Hours, and Night Shift. The calendars are templates that are used to create other calendar types. It’s recommended to only use base calendars for generic work periods. For example, you could create a base calendar specifically for your company that includes your typical work and non-work times. You can then use this base calendar as a template to create additional calendars. Base calendars are used to create all other calendar types.

If you’re using the Project Web App, only administrators can adjust the base calendars.

Project Calendars

Project calendars are base calendars that are customized for an individual project. When you create a new project in Microsoft Project, you will need to assign a project calendar. This calendar will determine the default working days and times for the entire project. Each task you add to the project will use the set project calendar, unless otherwise specified. For example, you may have a project with an assigned project calendar that works 4 days a week, 10 hours per day. By default, each task added to the project will be set to work 4 days a week, 10 hours a day based on this calendar.

You will need to assign all projects a project calendar. Like all calendars, project calendars are copies of base calendars adjusted for the specific project.

Task Calendars

Task calendars are base calendars that are customized for an individual project task. By default, each task will use the assigned project calendar – but you can adjust the individual task calendars as well. Each task within the project can use a different calendar. For example, you may have a project with an assigned project calendar for 5 days a week, 8 hours a day. We need to add a new task for the curing of concrete forms. This task will work 24 hours a day, 7 days a week. You can adjust this individual task’s calendar to specify its specific working days and hours.

Task calendars copies of base calendars adjusted and assigned to specific project tasks.

Resource Calendars

Resource calendars are base calendars that are customized for individual resources. By default, each resource will be assigned the project calendar – but you can switch this to a specific resource calendar. Each resource within the project can use a different calendar. This is very important, as resources may have PTO or specific times they are unavailable to work. Adding these times to a resource calendar will make sure the resource can work the tasks they’re assigned.

Like project and task calendars, resource calendars are base calendars adjusted and assigned to specific resources.

Although these different types of calendars are utilized differently, they are all created the same way. The calendar type generally depends on how you assign the calendar within the project.

Creating a New Calendar in Microsoft Project

First, open up a project within Microsoft Project. To create a new calendar, we will need to access the Main Ribbon, which will only display with a project open. If you’re planning on creating a project calendar, open up the project you’ll be creating the calendar for.

Within the Main Ribbon, select Project > Change Working Time.

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The Change Working Time window will open. Here, you can adjust the current calendars and create new ones. Under For calendar, you can see the 3 default calendars that come with the program:

  • Standard: This is a standard 8-hour workday calendar. This calendar is set to work from 8 AM to 5 PM with an hour-long lunch break at noon, Monday through Friday.

  • Night shift: This calendar reflects a standard graveyard shift schedule. It has a working period of Monday night through Sunday morning: 11PM to 8AM with an hour-long lunch break from 3AM-4AM.

  • 24 Hours: This calendar is set to work 24 hours a day, 7 days a week with no break period. This is generally used for activities that don’t require resources – such as an activity representing curing time.
Selecting any calendar from the list will allow you to view the calendars data and adjust it as needed. It’s generally recommended to not edit the base calendars, as you may want to use them again in the future. Instead, we can create a new calendar by selecting Create New Calendar.
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In the Create New Base Calendar column, you can give your new calendar a name. I’ll name mine Standard Work (5×8), meaning 5 days a week, 8 hours a day. It’s a good scheduling practice to include the standard working hours and days in the name of the calendar. Then, you can choose to create a new base calendar, or copy one of the existing calendars to use as a template.

If you want to create a base calendar to use on multiple projects, make sure to select Create a new base calendar. If you want to create a project, task, or resource calendar for the open project, select Make a copy of and choose a base calendar to use as a template.

In this example, I’ll be creating a project calendar, so I’ll choose to make a copy of a base calendar and select Standard. Then, press OK.

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Within the Change Working Time window, you’ll be in your newly created calendar. You can now adjust the calendar’s settings.
Creating the Standard Work Week
To start, you’ll want to set up the standard work week for the calendar. This is the standard working hours for each day of the work week, such as 8 to 5, Monday through Friday. To do this, select the Work Weeks tab. Here, you can create multiple standard work week periods, such as if your work week is different depending on the time of the year. There will already be a Default work week period created here – you can use this for the standard work week. To adjust this default work week, double click on the Default tab.
Here, we can select each day of the week and adjust their working times individually. Because all my working days will have the same work period, I’ll select Monday through Friday by selecting Monday, holding down Shift, and selecting Friday. Of course, you could always adjust specific days if there are differences in the work times.
Select the Set Days to Specific Working Times. This allows us to adjust the set working times listed. I’m going to shift my project’s working time to be from 7AM-4PM with a lunch break at 11AM. Simply click within the cells and type in the new times. Then, press OK. The changes will be noted within the Calendar window.
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Creating Additional Work Weeks

Let’s say that our project will use a different standard work week during certain times of the year. During the winter months, due to the lack of light, we will need to work from 8AM-5PM with a lunch break at noon. I can create a new standard work week period by selecting the blank cell under Default. I’ll give this period the name Winter.
Next to the work period will be a Start and Finish cell. These allows me to determine exactly when this work period will start being used and when it will stop. I’ll set the Start as December 1st and the Finish as February 28th. To do this, either select the dropdown arrow and use the calendar module, or type in a new date.
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Now, we can adjust the working period for the Winter months by double clicking on Winter. Again, I’ll select Monday through Friday, select Set days to these specific working times and set the desired times – 8AM to 12PM, 1PM to 5PM. Then, press OK.

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Now, the calendar will use the Default working week (7AM-4PM) for the majority of the year, but the Winter working week (8AM-5PM) from December to February.

Adding Exceptions and Holidays

Next, we can add Exceptions to our calendar, such as holidays or non-work periods. These are any dates or times that do not follow the standard work week – such as working weekends or non-working weekdays. We can do this by selecting the Exceptions tab. To add a non-working period to the calendar, select the first blank cell within the list. An Unnamed exception will appear, and we can type in a new name. For this project, there are a few weeks in the summer where work will not be performed. I’ll name this exception Summer Closure.
Next, we can select a Start and a Finish date for this exception. I’ll set this from July 1st to August 1st. If your exception will only be one day long, you can set the Start and Finish cells to the same date.
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You can adjust more options for this exception by selecting Details. Here, you can set specific working/non-working times for this period – such as if this exception was only going to affect some of the work hours. You can also choose whether this exception is going to reoccur – either daily, weekly, monthly, or yearly. I’ll select Yearly so this period is always non-working even in the upcoming years.
If you choose to set a recurrence pattern, you can also choose how many recurrence cycles to go through. In this case, how many years do we want to use this exception? My project is about 3 years in length, so I’ll set this to 4, just to be safe.
Then, press OK.
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I can continue to add exceptions as needed. You’ll want to add an exception for every non-working time within the project. You can always delete any exceptions by selecting Delete. These exceptions will show on the calendar once you click away.
Working Time Exceptions
You can also use exceptions for work days occurring on non-work times, such as weekends. Let’s say that we need to work this upcoming Saturday. I’ll set the date to start and finish this Saturday. Then, I can adjust the name as needed – I’ll name this Mandatory Meeting. Then, press Details. Here, select the Working times option and set the working times for that date. Press OK to exit out of the window.
That will also be marked on the calendar as an exception.
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Once you’re finished setting up the calendar, select OK. If you ever need to adjust any settings for this calendar or any other calendars, return to Project > Change Working Time.

Assinging the Calendar

With your calendar created, you can now assign it to projects, tasks and resources.

Assigning to a Project

To assign the created calendar to the open project, select Project > Project Information from the Main Ribbon. Under the Calendar field, select the calendar you created, then press OK.


Any new tasks or resources added to the project will use that project calendar by default.
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Assigning to a Task

To assign the created calendar to a project’s task, select the task and press Task > Information within the Main Ribbon. Under the Advanced tab, use the Calendar field and select the new calendar, then press OK.
Adjusting this task’s calendar will change when this task will be performed, but will not adjust any other tasks within the schedule.
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Assigning to a Resource

To assign the created calendar to a project’s resource, navigate to the Resource Sheet by selecting the shortcut in the lower right hand corner. You can also access this page by selecting Resource > View > Resource Sheet within the Main Ribbon.
Select the desired resource and press the Information button within the Resource menu. In the Resource Information box, select Change Working Time. The calendar window will open, where you can choose any of the created calendars to assign to the resource. Then, press OK, and OK again.
The assigned resource calendar will determine when this resource is available to work on any assigned tasks.
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Reusing Base Calendars

If you choose to create a base calendar, you can use the calendar on other projects you create in Microsoft Project. However, this will not be an option until you save the project as a template.
To save your project as a template to reuse the base calendar, select File > Export > Save Project as File > Project Template. Give your template a name and select Save. Within the Save As Template window, you can pick and choose what types of data to remove from the template. If you haven’t added any data to the project besides the calendar, you can leave all these options unchecked and select Save.
Once the template has been saved, you can create new projects from it. The template will have the base calendar saved to it for continuous use.
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In conclusion, calendars are vital in Microsoft Project for precise project scheduling. You will want to create as many calendars as needed to describe your project’s work. You can create Project calendars as base calendars, project calendars, task calendars, or resource calendars. One project can use many calendars to describe the different working days, hours, and exceptions needed for the schedule. Before creating tasks, make sure you have created and assigned a project calendar. Then, adjust each task and resource to their own calendars if needed. By doing this, Microsoft Project allows you to note when your tasks and resources can work throughout the project’s timeline.

If you have any comments, questions or suggestions, please use the comment section on the bottom of this page, and don’t forget to subscribe to our blog to get more scheduling tips & tricks directly in your inbox!

Lauren Hecker is an Oracle Primavera Cloud and Primavera P6 Instructor and teaches onsite and virtual scheduling courses. To see her next open enrollment course, please visit our calendar. To schedule an onsite or custom course, please contact us!


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