**As** an OpenProject user
**I want** to calculate the work package start and end dates based on the duration
**so** that I only have to set the duration.

# **Acceptance criteria:**

The duration feature affects a range of views and modules:

### Work package attributes and date picker

* In the date picker modal there is a text field `duration`.
* When the user enters a duration, the dates are derived.
* The contrary is also true: when a user enters dates, the duration is derived.
* More precise scenarios for what is derived/calculated as a result of what input (in which order), are [presented below](https://community.openproject.org/#scenarios).
* The duration represents the amount of days between the start and the finish date (inclusive):
* Monday to Tuesday: 2 days
* Monday to Monday (same day): 1 day
* Once configuring non-working days is implemented (<mention class="mention" data-id="18416" data-type="work_package" data-text="#18416">#18416</mention>), these non-working days are _skipped_ _over_ and do not count towards the total duration:
* Friday to Monday: 2 days _(Saturday and Sunday are skipped over)_
* **\[open\]** The user is able to override configured non-working days per work package; this means non-working can be optionally included, in which case they are _not_ skipped and count towards the date and duration count.
* **\[open\]** This requires manual scheduling to be checked (to be explored)
* In all cases, the duration is consistent with the start and the finish date. Updating dates will update duration, and updating duration will update dates.
* It will not possible, for example, to specify a duration of 8 days for a task that starts and finishes the same week.
* The duration as well as start and due dates can not be configured via the form configuration. They are always present at the same place within the work package show page and form.
* Work packages have an empty (not set) default duration.
* Setting start _and_ end dates automatically sets duration.
* Setting only one of the dates does not automatically set duration (unable to Begin of the insertionderive).End of the insertion Begin of the deletion derive)End of the deletion
* Setting only of the dates and duration derives the other date. Begin of the insertion
End of the insertion Begin of the deletion
End of the deletion * Begin of the insertionIt is possible to have _onlyEnd of the insertion Begin of the deletion **\[open\]** Duration, once set, cannot be removed unless at leastEnd of the deletion one Begin of the insertionattribute_ (only start date, only finish date or only duration) or all three. It is not possible to have just two (sinceEnd of the insertion Begin of the deletion ofEnd of the deletion the Begin of the insertionthird will be derived from the other two). Concretely:
* Duration specified; no start date; no finishEnd of the insertion dates Begin of the deletion (start/finish)End of the deletion is Begin of the insertionpossible.
* A start date specified; no finish date; noEnd of the insertion Begin of the deletion also removed; else,End of the deletion duration is Begin of the insertionpossible.
* A finish date specified; no start date; no duration is possible
but...
* A start date specified; duration specified; no end date is _not possible_. (End date is derived)
* A finish date specified; duration specified; no start date is _not possible_. (Start date is derived)
* A duration specified, start date specified, no finish date is _not possible_. (End date is derived)
* A duration specified, finish date specified, no start date is _not possible_. (Start datedate is derived).End of the insertion Begin of the deletion derived (as described above)End of the deletion
* Milestone-typed work packages don&#39;t have a duration Begin of the insertionfield.End of the insertion Begin of the deletion field. End of the deletion
* **\[open\]** On the GANNT and Team planner, they represent 1 day.
* The user has to to be informed when:
* Dates are automatically derived from relations (notably from parents or children),
* **\[open\]** The user must be given a way to view relations (a link to a GANTT view?)
* these automatically derived dates can not be modified, _unless:_
* Manual scheduling is enabled, and thus relations are ignored and
* Configured non-working days maybe optionally included in the calculation of total duration and start/end dates.

### Work package table view

* In the work packages list there is a column &quot;duration&quot;. When clicking on this the date modal with the date picker is opened.
* **\[open\]** With the focus on the duration field.
* Filtering by duration is possible
* Sorting by duration is possible

### GANTT chart

* For work packages without start/finish dates but _with_ duration, the width of a &quot;strip&quot; representing such a work package has a width that is relative to its total duration when dragging to the the GANTT chart.
* &quot;Relative&quot; because width depends on the zoom level of the GANTT chart.
* If the user modifies a work package via the drag handles on the left/right edges of the strips the in Gantt chart, both the start/finish date as well as the duration are altered in lockstep.

### Team planner

* For work packages without start/finish dates but _with_ duration, the width of a card that is dragged onto the team planner (from the left-hand &quot;Add Existing&quot; panel, for example) is relative to the total duration of that work package.
* &quot;Relative&quot; because width depends on the zoom level/view of the team planner calendar.
* If the user modifies a work package via the drag handles on the left/right edges of the cards on the Team planner, both the start/finish date as well as the duration are altered in lockstep.
* **\[open\]** The user is able to modify the view such that non-workin days are not displayed on the team planner.
* Even when non-working days are not displayed, they are nevertheless represented (although with much narrower column widths and without a Begin of the insertionheader).End of the insertion Begin of the deletion header). End of the deletion
* This is especially important because manual scheduling nevertheless allows users to include non-working days into the date and duration count.

# Open

* Visuals for the rework of the dates &amp; duration to be a fixed (not configurable) part of the work package show page and form (<mention class="mention" data-id="40539" data-type="work_package" data-text="#40539">#40539</mention>)
* Inheritance of the duration between a work package and its children
* e.g. can a work package have a duration that is less than the duration of its child

# Visuals needed

* Date picker with duration field
* Warning/Information when dates are derived from relations
* Warning/information about manual scheduling
* Option to include configured non-working days
* Work package table view with duration column
* GANTT view
* Team planner
* with option to switch on and off the display of non-working days in week/2-week view

# Scenarios

## Scenario 1:

* Setup
* Start date: Monday, February Begin of the insertion8,End of the insertion Begin of the deletion 8End of the deletion 2021
* Finish date: empty
* Duration: empty
* Change
* User enters a duration of 10 days
* Expected result:
* The finish date is Begin of the insertionsetEnd of the insertion Begin of the deletion changed toEnd of the deletion Friday, February 19 2021 Begin of the insertion(derived)End of the insertion

Begin of the insertion<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/28335/content"></div></figure>

End of the insertion ## Scenario 2

* Setup
* Start date: empty
* Finish date: empty
* Duration: empty
* Change
* User enters a duration of 10 days
* Expected result:
* No date is added

Begin of the insertion<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/28336/content"></div></figure>

End of the insertion ## Scenario 3

* Setup
* Start date: empty
* Finish date: Friday, February 19, 2021
* Duration: empty
* Change
* User enters a duration of 10 days
* Expected result:
* The start date is Begin of the insertionsetEnd of the insertion Begin of the deletion changedEnd of the deletion to Monday, February 8, 2021 Begin of the insertion(derived)End of the insertion

Begin of the insertion<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/28337/content"></div></figure>

End of the insertion ## Scenario 4

* Setup
* Start date: Monday, February 8, 2021
* Finish date: Friday, February 19, 2021
* Duration: 10
* Change
* User Begin of the insertionchangesEnd of the insertion Begin of the deletion enters aEnd of the deletion duration Begin of the insertiontoEnd of the insertion Begin of the deletion ofEnd of the deletion 11 days
* Expected result:
* The finish date is changed to Monday, February, 22 2021

Begin of the insertion<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/28338/content"></div></figure>

End of the insertion ## Scenario 5

* Setup
* Start date: Monday, February 8, 2021
* Finish date: Monday, February 22, 2021
* Duration: 11
* Change
* User Begin of the insertionchangesEnd of the insertion Begin of the deletion enters aEnd of the deletion duration Begin of the insertiontoEnd of the insertion Begin of the deletion ofEnd of the deletion 10 days
* Expected result:
* The finish date is changed to Friday, February, 19, 2021

Begin of the insertion<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/28339/content"></div></figure>

End of the insertion ## Scenario 6

* Setup
* Begin of the insertionStart date: Tuesday, February 9, 2021End of the insertion Begin of the deletion Two work packagesEnd of the deletion
* Begin of the insertionFinish date: Friday, February 12, 2021End of the insertion Begin of the deletion Task 1: Monday - Tuesday
* Task 2: no dates, no durationEnd of the deletion
* Change
* Begin of the insertionRemove duration.End of the insertion Begin of the deletion Task 2 follows Task 1End of the deletion
* Expected result
* Begin of the deletion Task 2: Starts Wednesday,End of the deletion Finish Begin of the insertiondate is also removed, start date is maintained as is.End of the insertion Begin of the deletion Date Wednesday, Duration = 1End of the deletion

Begin of the insertion<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/28340/content"></div></figure>

End of the insertion ## Scenario 7

* Setup
* Start date: Monday, February Begin of the insertion8,End of the insertion Begin of the deletion 9,End of the deletion 2021
* Finish date: Wednesday, February 11, 2021
* Duration: Begin of the insertion4End of the insertion Begin of the deletion 3End of the deletion
* Change
* User alters the start date to Begin of the insertionTuesday, February 9,End of the insertion Begin of the deletion Tuesday 10,End of the deletion 2021
* Expected result
* Begin of the insertion**\[behaviour updated\]**End of the insertion Finish date is Begin of the insertionmaintained, duration is automatically adjustedEnd of the insertion Begin of the deletion changedEnd of the deletion to Begin of the insertion3 days (derived; logic = changing date affects duration)End of the insertion Begin of the deletion Thursday, Feb 12, 2021End of the deletion

Begin of the insertion<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/28341/content"></div></figure>

End of the insertion ## Scenario 8

* Setup
* Start date: Tuesday, February Begin of the insertion9,End of the insertion Begin of the deletion 10,End of the deletion 2021
* Finish date: Begin of the insertionFriday,End of the insertion Begin of the deletion Thursday,End of the deletion February 12, 2021
* Duration: Begin of the insertion4End of the insertion Begin of the deletion 3End of the deletion
* Change
* User alters the finish date to Feb 11, Begin of the insertion2021.End of the insertion Begin of the deletion 2021End of the deletion
* Expected result
* Begin of the insertion**\[behaviour updated\]**End of the insertion Start date is Begin of the insertionunaffected, duration is now setEnd of the insertion Begin of the deletion changedEnd of the deletion to Begin of the insertion3 days (derived from dates).

<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/28342/content"></div></figure>

## Scenario 9

* Setup
* Start date: empty
* Finish date: empty
* Duration: 4
* Change
* User enters the finish date of Friday, February 12, 2021.
* Expected result
* The start date is set to Tuesday, FebruaryEnd of the insertion Begin of the deletion Monday, FebEnd of the deletion 9, 2021 Begin of the insertion(derived from duration).End of the insertion

Begin of the insertion<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/28343/content"></div></figure>

End of the insertion ## Scenario Begin of the insertion10End of the insertion Begin of the deletion 9End of the deletion

* Setup
* Start date: Begin of the insertionempty
* Finish date: Thursday, February 11, 2021
* Duration: empty
* Change
* User enters the start date of Tuesday, February 09, 2021
* Expected result
* Duration is set to 3 (derived from start date)

<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/28344/content"></div></figure>

## Scenario 11

* Setup
* Two work packages
* Task 1: 
* Start date:End of the insertion Monday, Begin of the insertion15 February, 2021
* End date: Wednesday, 17 February, 2021
* Duration: 3 
* Task 2:
* Start date: empty
* End date: empty
* Change
* Change relations such that Task 2 preceeds Task 1.
* Expected result
* Dates for Task 2 are derived from this &quot;proceeds&quot; relation.
* Start date: Friday, 12 February, 2021 (dates including and after the work package this one preceedes are blocked)
* Duration: 1 (automatic)
* End date: Friday, 12 February, 2021 (derived from duration)
* Warning: Reminder the start and end dates need to be before the dates of the work package this one is preceeding. Invalid dates are disabled.

<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/28347/content"></div></figure>

## Scenario 12

* Setup
* Two work packages
* Task 1:
* Start date: Monday, 8 February, 2021
* End date: Wednesday, 10 February, 2021
* Duration: 3
* Task 2:
* Start date: empty
* End date: empty
* Change
* Change relations such that Task 2 follows Task 1.
* Expected result
* Dates for Task 2 are derived from this &quot;follows&quot; relation.
* Start date: Thursday, 11 February, 2021 
* Duration: 1 (automatic)
* End date: Thursday, 11 February, 2021 (derived from duration)
* Warning: Reminder the start and end dates need to be after the work package this one following. Invalid dates are disabled.

<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/28348/content"></div></figure>

## Scenario 13

* Setup
* Two work packages
* Task 1:
* Start date: Monday, 8 February, 2021
* End date: Wednesday, 10 February, 2021
* Duration: 3
* Task 2:
* Start date: empty
* End date: empty
* Change
* Change relations such that Task 2 is a child of Task 1.
* Expected result
* Dates and duration for Task 2 are derived from the parent. 
* Start date: Monday, 8 February, 2021
* End date: Wednesday, 10 February, 2021
* Duration: 3
* Information: Reminder that this work package is now automatically scheduled, and that start and end dates are derived. The dates are not modifiable (unless manual scheduling is selected, which will ignore relations).

<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/28349/content"></div></figure>

## Scenario 14

* Setup
* Start date: Monday,End of the insertion February 9, 2021
* Finish date: Wednesday, February 11, 2021
* Duration: 3
* Change
* Begin of the insertionThe userEnd of the insertion Begin of the deletion UserEnd of the deletion moves the drag handle on the left border (start date) of the box representing the work package in Gantt chart and Team planner one day to the right (to Feb 10, 2021)
* Expected result
* The duration is reduced to 2. The start date is set to Feb 10, 2021. The Begin of the insertionfinishEnd of the insertion Begin of the deletion FinishEnd of the deletion date is left unchanged.

Begin of the insertion_(Visual will be added when ready)_

End of the insertion ## Scenario Begin of the insertion15End of the insertion Begin of the deletion 10End of the deletion

* Setup
* Start date: Begin of the insertionMonday, February 9, 2021End of the insertion Begin of the deletion emptyEnd of the deletion
* Finish date: Wednesday, February 11, 2021
* Duration: Begin of the insertion3End of the insertion Begin of the deletion emptyEnd of the deletion
* Change
* Begin of the insertionThe user movesEnd of the insertion Begin of the deletion User entersEnd of the deletion the Begin of the insertionwork package by dragging it to the right soEnd of the insertion start date Begin of the insertionis Wednesday,  Feb 11, 2021.End of the insertion Begin of the deletion of Monday, February 09, 2021End of the deletion
* Expected result
* Begin of the insertionThe durationEnd of the insertion Begin of the deletion **\[open\]** DurationEnd of the deletion is Begin of the insertionmaintained. Start state is now Wednesday, Febuary 11, 2021 (asEnd of the insertion set Begin of the insertionby drag), end date is setEnd of the insertion to Begin of the insertionFriday, February 13 (derived based on duration).

_(Visual will be added when ready)_End of the insertion Begin of the deletion 3End of the deletion

# Visuals

<figure class="image op-uc-figure"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/27172/content"></div></figure>

# Seed Data

**Static queries in section &quot;Default data&quot;:**

* Gantt chart: Add duration column after column finish date:

**Queries in section favorite views**

* Project plan (Query ID 1): Add duration column after column finish date
* Project plan (Query ID 14): Add duration column after column finish date

# Full screen view

* Currently the status selection is below the subject at the same position for all work package types.
* We also move the dates and the curation to this area (visuals tbd).
* For milestones there is no duration by definition.

# Out-of-Scope

* Consider weekends and holidays (for this ticket, will normally already have been dealth by <mention class="mention" data-id="18416" data-type="work_package" data-text="#18416">#18416</mention>)
* Summing duration _(need clarification)_
* Grouping by durations _(need clarification)_

# Implementation notes

* Frontend:
* include duration in date picker
* There is no duration form field for milestones.
* Restyling dates section (start &amp; due date &amp; duration) so that dates are always visible (no longer configurable via form configuration) similar to status
* Adapt specs that break by doing this
* Display longer bar in gantt chart and planning board while dragging a work package without start &amp; end dates
* Backend:
* Introduce into data layer &amp; contracts
* Disallow setting duration for milestone typed work packages
* Services
* **Open** inheritance within hierarchy
* Include in API
* Exclude for milestone typed work packages (should be covered by non writable property in contract)
* Calculates start/end dates on scheduling and on setting duration/start/end-dates
* Filter for duration (&quot;Everything longer than&quot;)
* Sort
* Seeding and default configurations
* Migration for removing the dates from existing form configurations as they can no longer be configured.
* Migration for setting a duration for all work packages having start and end date set.