Updating Date while deactivating user

 Create a custom field of text and date.

/* While deactivating a user on User Object update field on msg__c and deactivatedate__c with current dd*/  

Apex Class

public class deactivateHelper{

   

  public static Boolean isFirstTime = true;

    public static void updateUser(Set<id> pxyUsrId){

        

        system.debug('====='+pxyUsrId);

        //Getting the Id for the user

        Id userId = [select id,msg__c from User where id in: pxyUsrId limit 1].Id ; 

      //  List<User> userListToDeactivate = [select id,msg__c from User where id in: ids];

        

                List<User> uselst = new List<User>();

        if(pxyUsrId.size() > 0 ){

            for(user us : [SELECT Id, msg__c,deactivatedate__c from User WHERE Id = :userId]){

                system.debug('us'+us);

                us.msg__c = 'tested';

                us.deactivatedate__c=system.today();

                uselst.add(us);

            }

        }

        update uselst;

    }

}

Trigger

trigger deactivateUser on User (after update) {

    Set<Id> ids = new Set<Id>();

    if(deactivateHelper.isFirstTime)

        {

            deactivateHelper.isFirstTime = false;

            

            for(User  c: trigger.new){

                // checking if the user isactive

                if(c.isactive  == false){

                   

                    ids.add(c.Id);

                }

            }

        }

    System.debug(ids);

   if(ids.size() > 0){

    deactivateHelper.updateUser(ids);    

    }

}