I tried below query but its not working
select
TO_TIMESTAMP(ColumnName(Data type Date), 'DD-MON-YYYYHH24:MI:SS.FF')
from TableName
where Changedate>='01-Dec-2015'
*I need the result without AM/PM indication. Result will be 15-DEC-2015 15:16:42.045016
cast (column as timestamp)
?? – Benighted