PL/SQL :: Run 5 Scripts To Create 5 Tables

I need to run 5 scripts to create 5 tables, seems each table needs to take 2 hrs, so I plan to put all 5 commands together

so i would have tables.sql to contain the following

do you know how to add time in beginning and end , so I can figure it out how long does this take to create 5 tables, use spool too?

create table a as select * from ........ ;
create table b as select * from ........ ;
create table c as select * from ........ ;
create table d as select * from ........ ;
create table e as select * from ........ ;