Calendars tab

Calendars tab

Configure the working calendars used by your Gantt chart.

The Calendars tab allows you to define the working schedule used for project planning. You can configure the main chart calendar, create resource-specific calendars, reuse Global Calendars, and customize working days, working hours, holidays, and exceptions to build realistic project schedules.

On this page, you'll learn how to:

  • Configure the Main Chart Calendar

  • Add Resource Calendars

  • Use Global Calendars

  • Configure working days and working hours

  • Add calendar exceptions and overrides

  • Understand how calendars affect task scheduling


Main Chart Calendar

Every newly created Gantt chart initially uses the default calendar configured by a Jira administrator in Company-wide Configuration.

If needed, the chart manager can customize the calendar for an individual chart from the Calendars tab.

 

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Screenshot 2025-08-29 at 15.51.50.png

 

The Main Chart Calendar defines the default working schedule for the chart, including:

  • Working days

  • Working hours

  • Holidays

  • Calendar exceptions

Unless a task is assigned to a resource with its own Resource Calendar, scheduling is based on the Main Chart Calendar.


Resource Calendars

Resource Calendars allow you to define an individual working schedule for a specific resource within a chart.

To add a Resource Calendar:

  1. Open the Calendars tab.

  2. Click Add Chart Calendar.

  3. Select a resource.

If the selected resource has configured My Calendar (Personal Calendar), it is automatically used as the base calendar.

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Screenshot 2026-07-03 at 13.20.57.png

 

A Resource Calendar can inherit:

  • Working days

  • Working hours

  • Calendar exceptions

You can then customize the inherited schedule by changing working days, working hours, or adding additional overrides.

Note: Inherited overrides are displayed in blue and cannot be edited directly.

To save a Resource Calendar:

  1. Click OK in the Resource Calendar dialog.

  2. Click Save on the Calendars tab.


How Resource Calendar Inheritance Works

Resource Calendars remain linked to the user's Personal Calendar.

This means:

  • Working days and working hours continue to reflect changes made in the user's Personal Calendar unless they have been explicitly overridden in the chart.

  • Overrides created in the user's Personal Calendar are always inherited.

  • Additional overrides created in the chart remain independent and are preserved alongside inherited settings.

This approach keeps Resource Calendars synchronized with personal availability while allowing chart-specific adjustments when needed.


Example: Override a Personal Non-working Day

Suppose a resource marks September 8, 2025 as a non-working day in their Personal Calendar.

For a particular project, the chart manager needs that resource to work on that day.

Instead of changing the user's Personal Calendar, the chart manager simply adds a Working Day Override for September 8, 2025 in the Resource Calendar.

As a result:

  • the resource remains unavailable on that day in all other charts

  • the selected chart treats September 8 as a working day

  • work assigned on that date is scheduled normally


Resource Calendar Limitations

A chart manager cannot:

  • Create more than one Resource Calendar for the same resource.

  • Create a Resource Calendar without selecting a resource.

  • Edit another user's private Personal Calendar used as the base calendar.


How Calendars Affect Scheduling

Gantt Suite determines task scheduling using the following priority:

Tasks Assigned to a Resource Calendar

If a task is assigned to a resource with a configured Resource Calendar, scheduling is based on that calendar's:

  • Working days

  • Working hours

  • Calendar exceptions

Tasks Without a Resource Calendar

If a task is unassigned or assigned to a resource without a Resource Calendar, scheduling uses the Main Chart Calendar.

This ensures that every task always has a valid working schedule.


Global Calendars

The Calendars tab also allows chart managers to manage Global Calendars.

Global Calendars can be shared across multiple charts, making it easy to maintain consistent working schedules throughout the organization.

Typical uses include:

  • Company-wide working calendars

  • Regional calendars

  • Public holiday calendars

  • Department-specific schedules