Perform the following steps to add validation rules during a workflow transition:

1. Select and edit the workflow to configure.
2. Select the Diagram mode.
3. Select the Start Progress transition and click on the Validators link on the right-hand side.
4. Click on the Add validator link and select Date Compare (JSU) from the list.
5. Configure the validator with the following parameters:
   • The Start Date custom field for This date.
   • The greater-than sign, >, for Condition
   • Created for Compare with
   • An optional custom error message, or leave it blank and a default error message will be displayed if the validation fails

6. Click on Add to add the validator:

7. Click on Publish Draft to apply the change.

After adding the validator, if we now try to select a date that is before the issue's create date, Jira will prompt you with an error message and stop the transition from going through, as shown in the following screenshot:

As we can see, the date validation fails, and our custom defined error message is displayed.