Which calendar a task follows

Learning path
Go further in Learning path: Manage skills, people and capacity.

Summary: A task's working time comes from the calendar of whoever does the work (the resource behind a skill, or a Virtual skill's own calendar), while the project's calendar and Hours per day decide how that time is counted in days.

Applies to

Property	Value
Product	LYNX-X
Version	28.10.9846.0
Required permissions	Space administrator for calendars, resources and skills; read and write access to the project
Last updated	2026-10-12
Owner	Support

Definition

Four calendars can have a say in one task. Each answers a different question.

Calendar	Set in	Answers
Project calendar and Hours per day	Project properties › General	How long is a "day" when this project counts durations?
Resource calendar	Configuration › Resources › Details › Calendar	When does this person work?
Skill calendar	Configuration › Skills › Scheduling	When can a Virtual skill work? It has no people of its own.
Parent calendar	Configuration › Calendars › New › Parent	Which rules does a calendar inherit?

A calendar can be built on another. When you create one, the Parent field lets you start from an existing calendar.

The New calendar dialog with its Parent field

The new calendar takes its parent's days off and public holidays, and its own rules replace only what you change. Below, 6 h day keeps Standard's weekends and holidays and replaces the working hours with 9:00 to 15:00.

A 6-hour calendar built on Standard

Purpose

When a task takes longer than its hours suggest, the cause is usually one of these calendars. Knowing which one applies tells you where to look and what to change.

The order, from the project up:

The project defines the task. Its calendar and Hours per day turn a duration into hours: 5 days on a 6-hour day are 30 hours of work. Keep the two in step; when they disagree, the day counts stop meaning working days.
The skill works those hours. A Virtual skill works them to its own Skill calendar. A Normal skill takes the calendar of the person LYNX-X binds to it.
The person's calendar rules on top. With Individual calendars on, the task shows in the assigned person's time. A longer working day than the project's makes the task shorter; a shorter one makes it longer.

Which calendar rules a task, and what it does to a 5-day task

Examples

The plan has three tasks of 40 hours each. It starts on a Monday, on the Standard calendar with Hours per day 8:00. Every task gets its work through a skill. On Run acceptance tests, the person behind the skill, Warren Barguil, is hard-assigned, because his own calendar is what the examples change.

The skill decides whose calendar applies

One plan, three tasks: two Normal skills and one Virtual skill

Install test rig and Run acceptance tests use Normal skills. Their people work the Standard 8-hour day, so 40 hours take [5 days].
Write test report uses a Virtual skill, Report Writer. Its Skill calendar is Friday Free, a four-day week. The same 40 hours take [6 days].

The Assignments row reads 5 days/40h at 100 % in every case. The work is the same; only the calendar it is done in differs.

A Virtual skill's calendar is set on its Scheduling tab. For a Normal skill that field is greyed, because a Normal skill takes its calendar from its resources.

A Virtual skill with its own Skill calendar

A person's own calendar stretches the task

Put Warren Barguil, who does the Field Technician's work, on the 6 h day calendar. The calendar is a field on his resource:

Warren Barguil's own calendar

Change nothing else:

The same 40-hour task, done by someone on a 6-hour day

Run acceptance tests now takes [6,5 days]. The assignment still reads 5 days/40h at 100 %: the hours have not changed, they are done six at a time.

Note
Resource calendars apply when Individual calendars is on in the space's properties. All the examples here were made with it on.

The project calendar and Hours per day must agree

Set the project calendar to 6 h day, but leave Hours per day at 8:00:

Project calendar and Hours per day out of step

The bars do not move: the work is done at the same time as before. Only the counting changes, and the day counts now mix two definitions of a day. The tasks done by 8-hour people read [3,8 days] and the Virtual skill's [4,5 days]. None of these is the number of working days anyone spends on the task.

Set Hours per day to 6:00 to match the calendar:

Project calendar and Hours per day in step

The tasks read [5 days], [5 days] and [6 days] again: each person's real working days.

Once a project is Released, Hours per day can no longer be changed. Decide it before you release.

Key concepts

Hours are fixed, days are derived. The hours on an assignment stay the same; calendars decide over how many days they spread.
Normal skill: the resource's calendar. Virtual skill: the skill's calendar. The project calendar does not override either. It only sets how days are counted.
One definition of a day per project. Keep the project calendar's working day and Hours per day equal.
Fewer calendars, clearer plans. A-dato's advice is not to create more calendars than you need. Each one is another place a duration can come from.

Setting up a calendar
Assigning calendars to resources, skills and projects
How resource availability affects task duration
What 100 % means: choosing how to model availability

Revision history

Version	Date	Author	Changes
1.0	2026-10-09	Support	New article.

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