Batch Class:::

global class BatchclasstoSendMail implements Database.Batchable <Sobject> {

     global Database.QueryLocator start(Database.BatchableContext bc){

     string query = 'select name,Email, Birthdate from Contact where Email != null';
     system.debug('******'+query);
     return Database.getQueryLocator(query);
     }

     global  void execute(Database.BatchableContext bc, List<Contact> lst){
  list<Messaging.SingleEmailMessage> mail = new list<Messaging.SingleEmailMessage>();
          for(Contact c: lst){
            Messaging.SingleEmailMessage objEmail = new Messaging.SingleEmailMessage();
            list<string> toadd=new list<string>();
            toadd.add(c.Email);
            system.debug('*****'+c.Email);
            objEmail.setToAddresses(toadd);
            system.debug('*****'+toadd);
            objEmail.setsubject('Your contact was registered successfully');
            objEmail.setplaintextbody('you are most valuable person we will contact you  as soon as possible');
            mail.add(objEmail); 
              system.debug('*****AllMails'+objEmail);
          }           
   Messaging.SendEmailResult[]  result =Messaging.sendEmail(mail);
         
      } 

     global void finish(Database.BatchableContext BC){
     System.debug(BC);
       
     }
   
} 
Scheduled Class::

global class ScheduledBatchToSendMail implements schedulable {
global  void execute(SchedulableContext sc){
        BatchclasstoSendMail myBatchClass = new BatchclasstoSendMail();
            database.executeBatch(myBatchClass);
    }
}

Excecution scheduled class form DevConsole:::

ScheduledBatchToSendMail m = new ScheduledBatchToSendMail();
String sch = '0 30 18 ? * WED *';
String jobID = system.schedule('Merge Job', sch, m);