Send Account's Agreement Termination notification mail before two days of termination date

 Create a schedulable batch class as below:

Apex class:

global class NotificationEmailtoAccountExecutive implements Database.Batchable < sObject >, Schedulable, Database.Stateful 

{

    global List<String> errorMessages = new List<String>();

    global Database.QueryLocator start(Database.BatchableContext bc) 

    {

        Date ed = Date.today().addDays(2); // add two days for sending mail before two days 

        System.debug('date after add two days: '+ed);

        string query = 'SELECT id,name,(select id from contacts),  Agrrement_Termination__c FROM account where  Agrrement_Termination__c =: ed';

        system.debug('my Query is '+query);

        return Database.getQueryLocator(query);

    }

    global void execute(Database.BatchableContext bc, List < account > recs) {

        List < Messaging.SingleEmailMessage > mailList = new List < Messaging.SingleEmailMessage > ();

        for (account a: recs) {

            if (a.Agrrement_Termination__c != null) {

                List < String > toAddresses = new List < String > ();

                Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();

                toAddresses.add('test@test.com');// to Acc Executive mail/or manager mail

                mail.setToAddresses(toAddresses);

                id tempId = [select id from emailTemplate where name='Termination popup' limit 1].id;

                mail.setTemplateId(tempId); // set Tempplate id

                mail.setSaveAsActivity(false);

                mail.setWhatId(a.id);

                mail.setTargetObjectId('0036F00003gR4TUQA0');// not send just for using the template id because emailTemplat need this

                mail.setTreatTargetObjectAsRecipient(false);

                mail.setWhatId(a.id);

                mailList.add(mail);

            }

        }

        Messaging.sendEmail(mailList);

    }

    global void finish(Database.BatchableContext bc)

    {

        system.debug('Finish method call');

        

    }

    global void execute(SchedulableContext SC) {

        NotificationEmailtoAccountExecutive batchable = new NotificationEmailtoAccountExecutive();

        database.executebatch(batchable);

    }

}

=================================================================

Schedule  this method according to your choice.

REF:ak@infoglen.com