Datetime Format Models
Use datetime format models in the following functions:
- 
                        In the TO_CHAR,TO_DATE, andTO_TIMESTAMPfunctions to translate a character value that is in a format other than the default format for a datetime value.
- 
                        In the TO_CHARfunction to translate a datetime value that is in a format other than the default format into a string.
The total length of a datetime format model cannot exceed 22 characters.
The default american_america NLS language and territory setting are used.