Calendar management
ORGANIZATION > User management > Calendars
The Calendars menu allows you to create and manage calendars for your company. Calendars define non-working days for your organization. For example, if your company operates in multiple regions, you can create a calendar for each region and assign it to users accordingly. You can also create calendars for holidays or special events.
When creating a calendar, you can:
- Set its name
- Define non-working days
- Designate it as the default calendar for the company
Creating a new calendar
To create a calendar different from the default, go to:
ORGANIZATION > User management > Calendars and click Add new calendar.

Select non-working days for this calendar.

Then, assign this schedule to users in the User management section.

Uploading non-working days via CSV
You can also upload non-working days using a CSV file by downloading a template and importing the data.
User calendar section
MANAGEMENT > Users > [User] > Calendar
Each user has two initially assigned calendars:
- Default organization calendar: Defined in the User management > Calendars section.
- Personal calendar: Includes user-specific holidays and leave days.
Additionally, you can assign account-level calendars, such as regional holiday calendars. Assigned calendars affect:
- Non-working days
- Availability
- Effort estimation
- Hour distribution
When a calendar is added or modified, ITM Platform recalculates the user's task effort distribution accordingly.
Managing user calendars
In a user's Calendar tab, you will see:
- The default company calendar
- The personal calendar (for individual holidays and leave)
- Any account-level calendars assigned to the user
For example, if your company has regional calendars, you can add them here to ensure accurate scheduling for users in different locations.
Assigning calendars to projects
In addition to assigning calendars to users, you can assign a specific Holiday Calendar to each project. This overrides the account's default calendar for that project's scheduling calculations.
When a project has no custom calendar assigned, it uses the account's default Holiday Calendar — the same behavior as before.
How to set a project's calendar
- Open the project and go to the General tab.
- Find the Holiday Calendar dropdown.
- Select the desired calendar, or choose "Default" to use the account's default settings.
- Save the project.
When you change the calendar from its saved value, an orange warning icon appears next to the dropdown. Hovering over it explains that saving will recalculate task and project durations and unassigned effort, without changing dates.
What project calendars affect
- Gantt chart — Non-working days (shaded columns) reflect the project's calendar
- Duration calculations — The number of working days between task start and end dates uses the project's calendar
- Unassigned effort distribution — Working days for effort allocated to a category (not a specific person) are determined by the project's calendar
- AI-generated plans — Date calculations use the project's calendar
- Revenue recognition — Working-day counts for revenue models use the project's calendar
What is NOT affected
- Individual user schedules — Each team member's personal Working Hours and holidays remain unchanged. Timesheets, per-user effort distribution, and Resource Analysis continue to use each person's individually assigned schedule.
- Portfolio and Program Gantt — These aggregate views continue using the account-level defaults.
Changing a project's calendar after tasks exist
You can change a project's calendar at any time. Task dates stay the same, but durations recalculate automatically based on the new working days. The Gantt chart updates accordingly, and unassigned effort is redistributed.
Deletion protection
If a Holiday Calendar is assigned to one or more projects, it cannot be deleted. You will see a message indicating how many projects are using it. To delete the calendar, first reassign each project to a different calendar or switch back to Default.