How to to find the  timestamp for rebuild index and Gather Stats:-

 for rebuild index:-

select TO_CHAR(last_ddl_time,'DD-MON-YYYY HH24:MI:SS') DDL,timestamp from
dba_objects where object_name like '%GL_JE_LINES_U1%';


 for gather stats:-

select last_analyzed from dba_indexes where index_name like '%GL_JE_LINES_U1%';