validation - Verifying format of 'date'/'timestamp'/'timestamp with time' zone type parameter in oracle script -

i need verify format of input parameter of 'timestamp time zone' type. passed substitution variable in script. format 'yyyy-mm-dd hh24:mi:ss tzh:tzm'. how should verify passed value given format. oracle function use this?

i cannot use to_timestamp_tz function convert char-exp timestamp tz. here want validate format of passed 'timestamp time zone' variable.

you can use to_timestamp_tz ex:

select to_timestamp_tz('1999-12-01 11:00:00 -8:00',    'yyyy-mm-dd hh:mi:ss tzh:tzm') dual;