alter table EXECUTION_PERIOD add column TEACHER_CREDITS_PERIOD_BEGIN timestamp NULL default 0;
alter table EXECUTION_PERIOD add column TEACHER_CREDITS_PERIOD_END timestamp NULL default 0;
alter table EXECUTION_PERIOD add column DEPARTMENT_ADM_OFFICE_CREDITS_PERIOD_BEGIN timestamp NULL default 0;
alter table EXECUTION_PERIOD add column DEPARTMENT_ADM_OFFICE_CREDITS_PERIOD_END timestamp NULL default 0;