How can we restrict Technician to assign Schedule End Date on Task less than Schedule End Date assigned on the Change Request?

How can we restrict Technician to assign Schedule End Date on Task less than Schedule End Date assigned on the Change Request?

Dear All,

While creating a Change Request we've set the Scheduled Start and Scheduled End for 1 Month but while creating a Task manually under the Implementation Stage of the Change Request we can able to set the Schedule End above 1 Month from the actual Scheduled End Date Set on the Change Request.

How can we allow the Technician to assign the Scheduled End Date Less than the Scheduled End Date assign to the Change Request only?

Regards,
Wajahath Farooq