Is it possible to set the validation for the custom field(e.g Date Picker) value by JIRA administrator?

[kesavan bakthavatsalam]

Is it possible to set the validation for the custom field(i.e Date Picker) value? For example, JIRA should validate if the date entered in the custom field is the current date and should not allow to enter the future date.

[Deniz Oğuz - The Starware]

You can do it with a workflow validator scripts, please check Script Runner documentation https://scriptrunner.adaptavist.com/latest/jira/recipes/workflow/validators/simple-scripted-validators.html