Updating Task Dates: How Shotgun Thinks

When updating Task dates in an API update() request, there is no specified order to the values that are passed in. Shotgun also does automatic calculation of the start_date, due_date, and duration fields for convenience. In order to clarify how updates are handled by Shotgun we are providing some general rules below and examples of what will happen when you make updates to your Tasks.

General Rules

• Updating the start_date automatically updates the due_date (duration remains constant)

• Updating the due_date automatically updates the duration (start_date remains constant)

• Updating the duration automatically updates the due_date (start_date remains constant)

• When updating Task values, Shotgun sets schedule fields (milestone, duration, start_date, due_date) after all other fields, because the Project and Task Assignees affect schedule calculations.

• If start_date and due_date are both set, duration is ignored (duration can often be wrong since it's easy to calculate scheduling incorrectly).

• If both start_date and due_date are provided, Shotgun sets start_date before due_date.

• Set milestone before other schedule fields (because start_date, due_date, and duration get lost if milestone is not set to False first)

• If milestone is being set to True, duration is ignored.

• If milestone is set to True and start_date and due_date are also being set to conflicting values, an Exception is raised.

• If due_date and duration are set together (without start_date), duration is set first, then due_date (otherwise setting duration will change due_date after it is set).

Examples

The following examples show what the resulting Task object will look like after being run on the initial Task object listed under the header of each section.

Universal

Regardless of current values on the Task, this behavior rules

Task = {'start_date': '2011-05-20', 'due_date': '2011-05-25', 'duration': 2400, 'id':123}

Update start_date and due_date

duration is ignored if also provided. It is instead set automatically as (due_date - start_date)

sg.update ('Task', 123, {'start_date':'2011-05-25', 'due_date':'2011-05-30', 'duration':1200})
# Task = {'start_date': '2011-05-25', 'due_date': '2011-05-30', 'duration': 2400, 'id':123}

start_date is updated. due_date is updated. duration is calculated as (due_date - start_date) **note the value provided in the update() is ignored. (and in this case was also incorrect).

Update start_date and duration

sg.update ('Task', 123, {'start_date':'2011-05-25', 'duration':3600})
# Task = {'start_date': '2011-05-25', 'due_date': '2011-06-01', 'duration': 3600, 'id':123}

start_date is updated.
duration is updated. due_date is updated to (start_date + duration).

Update due_date and duration

sg.update ('Task', 123, {'due_date': '2011-05-20', 'duration':3600})
# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-20', 'duration': 600, 'id':123}

duration is updated.
due_date is updated. duration is calculated as (due_date - start_date) note that this means the duration provided is overwritten and thus ignored.

Task has start_date only

Task = {'start_date': '2011-05-20', 'due_date': None, 'duration': None, 'id':123}

Update start_date

sg.update ('Task', 123, {'start_date':'2011-05-25'})
# Task = {'start_date': '2011-05-25', 'due_date': None, 'duration': None, 'id':123}

Only start_date is updated.

Update due_date

sg.update ('Task', 123, {'due_date':'2011-05-25'})
# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-25', 'duration': 2400, 'id':123}

due_date is updated.
duration is updated to (due_date - start_date).

Update duration

sg.update ('Task', 123, {'duration':2400})
# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-25', 'duration': 2400, 'id':123}

duration is updated.
due_date is set to (start_date + duration)

Task has due_date only

# Task = {'start_date': None, 'due_date': '2011-05-25', 'duration': None, 'id':123}

Update start_date

sg.update ('Task', 123, {'start_date':'2011-05-20'})
# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-25', 'duration': 2400, 'id':123}

start_date is updated.
duration is updated to (due_date - start_date).

Update due_date

sg.update ('Task', 123, {'due_date':'2011-05-20'})
# Task = {'start_date': None, 'due_date': '2011-05-20', 'duration': None, 'id':123}

only due_date is updated.

Update duration

sg.update ('Task', 123, {'duration':2400})
# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-25', 'duration': 2400, 'id':123}

duration is updated.
start_date is set to (due_date - duration)

Task has duration only

# Task = {'start_date': None, 'due_date': None, 'duration': 2400, 'id':123}

Update start_date

sg.update ('Task', 123, {'start_date':'2011-05-20'})
# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-25', 'duration': 2400, 'id':123}

start_date is updated.
due_date is updated to (start_date + duration).

Update due_date

sg.update ('Task', 123, {'due_date':'2011-05-25'})
# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-25', 'duration': 2400, 'id':123}

due_date is updated.
start_date is updated to (due_date - duration)

Update duration

sg.update ('Task', 123, {'duration':3600})
# Task = {'start_date': None, 'due_date': None, 'duration': 3600, 'id':123}

only duration is updated.

Task has start_date and due_date (no duration)

# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-25', 'duration': None, 'id':123}

Update start_date

sg.update ('Task', 123, {'start_date':'2011-05-25'})
# Task = {'start_date': '2011-05-25', 'due_date': '2011-05-25', 'duration': 600, 'id':123}

start_date is updated.
duration is updated to (due_date - start_date).

Update due_date

sg.update ('Task', 123, {'due_date':'2011-05-30'})
# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-30', 'duration': 4200, 'id':123}

due_date is updated.
duration is updated to (due_date - start_date)

Update duration

sg.update ('Task', 123, {'duration':3600})
# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-27', 'duration': 3600, 'id':123}

duration is updated.
due_date is updated to (start_date + duration)

Task has start_date and duration (no due_date)

# Task = {'start_date': '2011-05-20', 'due_date': None, 'duration': 2400, 'id':123}

Update start_date

sg.update ('Task', 123, {'start_date':'2011-05-25'})
# Task = {'start_date': '2011-05-25', 'due_date': '2011-05-30', 'duration': 2400, 'id':123}

start_date is updated.
due_date is updated to (start_date + duration).

Update due_date

sg.update ('Task', 123, {'due_date':'2011-05-30'})
# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-30', 'duration': 4200, 'id':123}

due_date is updated.
duration is updated to (due_date - start_date).

Update duration

sg.update ('Task', 123, {'duration':3600})
# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-27', 'duration': 3600, 'id':123}

duration is updated.
due_date is updated to (start_date + duration)

Task has due_date and duration (no start_date)

# Task = {'start_date': None, 'due_date': '2011-05-25', 'duration': 2400, 'id':123}

Update start_date

sg.update ('Task', 123, {'start_date':'2011-05-25'})
# Task = {'start_date': '2011-05-25', 'due_date': '2011-05-30', 'duration': 2400, 'id':123}

start_date is updated.
due_date is updated to (start_date + duration).

Update due_date

sg.update ('Task', 123, {'due_date':'2011-05-30'})
# Task = {'start_date': '2011-05-25', 'due_date': '2011-05-30', 'duration': 2400, 'id':123}

due_date is updated.
start_date is updated to (due_date - duration).

Update duration

sg.update ('Task', 123, {'duration':3600})
# Task = {'start_date': '2011-05-18', 'due_date': '2011-05-25', 'duration': 3600, 'id':123}

duration is updated.
start_date is updated to (due_date - duration)

Task has start_date, due_date, and duration

# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-25', 'duration': 2400, 'id':123}

Update start_date

sg.update ('Task', 123, {'start_date':'2011-05-25'})
# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-30', 'duration': 2400, 'id':123}

start_date is updated.
due_date is updated to (start_date + duration).

Update due_date

sg.update ('Task', 123, {'due_date':'2011-05-30'})
# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-30', 'duration': 4200, 'id':123}

due_date is updated.
duration is updated to (due_date - start_date)

Update duration

sg.update ('Task', 123, {'duration':3600})
# Task = {'start_date': '2011-05-20', 'due_date': '2011-05-27', 'duration': 3600, 'id':123}

duration is updated.
due_date is updated to (start_date + duration)