By default, the Task Due Date is based on the current date. So if the value is 2, the due date is two (working) days after the Tasks prerequisites (if any) have been completed.
This feature allows to calculate backwards.
Examples are a Release or a Meeting preparations to meet a target date.
With a negative relative date, the Due Date is calculated based on the Target Date.
In the Checklist Item, use a negative value for the Date Offset Days.
You can mix positive (based on the current date) and negative values in the checklist.
Optionally, you can default the Target Date from the record. In the Checklist, set the Dynamic Target Date - a reference to the date field (use the api name like MyDate__c)
- example: Use the Clise Date in the Opportunity as the Target Date
When creating the Tasks from the Checklist, enter the target date.
When you change the Target Date, the Due Dates are updated based on the Date Offset.
The date is stored in the Checklist Instance and you can update there, if required.
Update of the Target Date
You can manually update the Target date in the checklist instance or update the Target date from the (changed) record date. Example: the Opportunity Close Date changed and you want to update the checklist tasks.
Manual Target Date Update when Record changed
- In the Tab Checklist, select any List (other than Recently Viewed) and click "Instance Maintenance" - or
- In the Tab Checklist, select any checklist record and select "Instance Maintenance"
In the Form,
- select e.g. -all- checklists -- by default the instances of this checklist are updated
- click on Update Target Date
This updates the Checklist Instance if the target date of the record was changed and also updates the Activity Date of the Tasks.
Automatic Target Update
In Setup > Apex Classes
click on "Schedule Apex"
- Select the Apex Class: CheckListTargetUpdate
- Enter Name, Frequency and Start/End date
(note that Salesforce does not notify you when the job expired)