Here is the script and kindly follow the steps below to achieve your requirement to send Auto reminders to Change Approvers after X days. For now, the script sends reminder for every 24 and 48 hours. This can be customized in the script.
1.Download the contents and paste it under \ManageEngine\ServiceDeskPlus-MSP\integrations\Custom_scripts
2.Execute the below Query under Reports->New Query tab and save the query.
select changestatuscomments.changeid "workorderid", aaacontactinfo.emailid "emailid", changestatuscomments.commentedon "last_tech_update" from changestatuscomments inner join changedetails on changestatuscomments.changeid = changedetails.changeid inner join changeroleusermapping on (changeroleusermapping.changeid = changedetails.changeid) inner join aaausercontactinfo on (changeroleusermapping.userid = aaausercontactinfo.user_id) inner join aaacontactinfo on (aaausercontactinfo.contactinfo_id = aaacontactinfo.contactinfo_id) where changestatuscomments.wfstageid =(select wfstageid from change_stagedefinition where name like '%planning%') and changestatuscomments.wfstatusid =(select wfstatusid from change_statusdefinition where statusname like '%approved%' and wfstageid =(select wfstageid from change_stagedefinition where name like '%planning%')) and changedetails.appr_statusid =(select statusid from approvalstatusdefinition where statusname like '%pending%' ) and aaacontactinfo.emailid is not null and changeroleusermapping.roleid=(select id from changeroles where name='ChangeApprover');
3.Configure Custom Schedule for every one hour. So, query will run for every 1 hour and check if there is any approver to be reminded. 1 hour is the minimum, so reminder will be sent 24 + 1 Hour maximum.