> ## Documentation Index
> Fetch the complete documentation index at: https://docs.dash360.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Project Calendar
> Build the project's working calendar: work week, hours per day, and holidays; then generate the period table and the Hours and FTE rate sets.
## Overview
The project calendar defines what counts as working time: which days of the week are work days, how many hours are in one of them, and which dates are holidays. Two things depend on it:
* **The schedule Monte Carlo simulation** steps durations forward through working days, so the calendar decides whether a simulated 30-day activity finishes in six weeks or seven.
* **The Hours and FTE rate sets**, which are generated from the calendar's period table and saved onto the project's rate file.
**Location:** Admin > Projects > Edit Project > **Calendar** tab.
Prefer to watch? See [How to Set Up Spread Profiles and Calendars](/user-guide/risk/how-to/spread-profiles-and-calendars) for a video walkthrough.
## Prerequisites
* Your account must have administrative access to the project.
* The project needs its Start Date and Finish Date set, along with a resource file and a rate file. All five are shown read-only at the top of the tab for reference.
***
## Creating a calendar
Click **Add Calendar** to open the form.
| Field | Description |
| -------------------------------- | ------------------------------------------------------------------------------------------------------------- |
| **Calendar Name** | The label for this calendar |
| **Set As Default** | Marks this as the calendar the project uses. See [Which calendar gets used](#which-calendar-gets-used) below. |
| **Start Date** / **Finish Date** | The span the calendar covers. These pre-populate from the project's own dates. |
| **Hrs/Day** | Working hours in a single work day (1 to 24; defaults to 8) |
| **Weekly Work Days** | Tick the days that count as working days. **Quick Select** offers Mon-Fri, Mon-Sat, All Days, and Clear All. |
Click **Generate Calendar** to build the period table from those settings.
**Generate Calendar rebuilds the period table.** Running it again on an existing calendar recreates its periods and the Hours and FTE values derived from them. Use it when you intend to rebuild, not as a way to refresh the display.
***
## Calendar Periods
Once generated, the **Calendar Periods** tab shows one row per month:
| Column | Description |
| ----------------- | ----------------------------------------------------------------------- |
| **Date** | The period |
| **Working Days** | Days in the period that fall on a ticked work day and are not a holiday |
| **Working Hours** | Working Days multiplied by Hrs/Day |
| **Hours Rate** | The value written if you save an Hours rate set |
| **FTE Rate** | 1 FTE divided by the total working hours for that month |
A total row is pinned to the bottom with the calendar's overall working days and hours. Because month lengths and holidays differ, expect the per-month working days to vary (typically 20 to 23 on a Monday to Friday calendar).
A **Labels** tab sits alongside Calendar Periods for custom period labels, where your organization reports on named periods rather than raw month names.
***
## Holidays
The Holidays panel sits beside the period table.
1. Pick a **Holiday Date**.
2. Tick **Is Yearly Holiday** if the date should repeat every year the calendar covers.
3. Click **Add Holiday**.
The list keeps a running count in a badge, and **Delete All** clears every holiday at once.
A holiday removes one day from the Working Days count for the period it falls in, which is what makes simulated durations step over it.
Add holidays **before** generating, or regenerate afterward. The period table is built from the settings as they stood when you clicked Generate Calendar, so holidays added later are not reflected until it is rebuilt.
***
## Saving rate sets
**Save Hours Rate Set** and **Save FTE Rate Set** write the generated column values into a named rate set on the project's current rate file. You are prompted for a rateset name, which must be unique for that rate file.
Choosing an **existing** rateset name deletes and recreates every rate in that rateset to match the generated table. A confirmation step appears before the overwrite happens.
Click **Save** or **Save & Close** to store the calendar itself.
***
## Which calendar gets used
A project can hold more than one calendar, so the simulation picks by the **Set As Default** flag.
If no calendar is marked as default, or the project has no calendars at all, the schedule simulation falls back to a standard five-day work week (Monday to Friday) with **no holidays**.
The fallback applies just as much when calendars exist but none is flagged as default. Building a calendar is not enough on its own; if you want holidays and a non-standard work week to affect simulated finish dates, one calendar must be set as the default.
***
## Where the calendar is used next
* **Schedule simulation:** see the [Risk Analysis](/user-guide/risk/risk-analysis) guide for how durations are sampled and stepped.
* **Rate sets:** the saved Hours and FTE rate sets become selectable on the project's rate file. See [Rates](/user-guide/admin/rates).