Convert String ISO-8601 date to oracle's timestamp datatype

The date format model elements are listed in the Datetime Format Models documentation:

SELECT to_timestamp_tz ('2014-09-12T11:53:06+00:00', 'YYYY-MM-DD"T"HH24:MI:SSTZH:TZM')
FROM DUAL

TO_TIMESTAMP_TZ('2014-09-12T11:53:06+00:00','YYYY-MM-DD"T"HH24:MI:SSTZH:TZM')
---------------------------------------------------------------------------
12-SEP-14 11.53.06.000000000 +00:00

The fixed T can be included as a character literal:

You can include these characters in a date format model:

• Punctuation such as hyphens, slashes, commas, periods, and colons
• Character literals, enclosed in double quotation marks

TZH is tome zone hour, and TZM is time zone minutes. The rest are more common model elements.