Interval formatting mask

An interval formatting mask specifies a format to apply to some interval value. This mask must be combination of Class 1 interval or Class 2 interval formatting directives:

Table 1. Class 1 formatting directives ( YEAR to MONTH ) for the INTERVAL data type
Character	Description
`%C`	Identifies century number (year divided by 100 and truncated to an integer)
`%iy`	Identifies the year as a 2-digit number (00 to 99).
`%iY`	Identifies the year as a 4-digit number (0000 to 9999).
`%m`	Identifies the month as a number (01 to 12). Single digit is preceded by zero.
`%y`	Identifies the year as a 2-digit number (00 to 99).
`%Y`	Identifies the year as a 4-digit number (0000 to 9999).

Table 2. Class 2 formatting directives ( DAY to FRACTION ) for the INTERVAL data type
Character	Description
`%a`	Identifies abbreviated weekday name as defined in locale.
`%A`	Identifies full weekday name as defined in locale.
`%d`	Identifies the day of the month (01 to 31). Single digit is preceded by zero.
`%e`	Identifies the day of the month as a number (1 to 31). Single digit is preceded by space.
`%Fn`	Identifies value of the fraction of a second, with precision specified by integer n. Range of n is 0 to 5.
`%H`	Identifies the hour as 24-hour clock integer (00-23).
`%I`	Identifies the hour as 12-hour clock integer (00-12).
`%M`	Identifies the minute as an integer (00-59).
`%S`	Identifies the second as an integer (00-61). Second can be up to 61 instead of 59 to allow for the occasional leap second and double leap second.
`%w`	Identifies the weekday as a number (0 to 6), where 0 is the locale equivalent of Sunday.

Table 3. Specials formatting directives ( DAY to FRACTION ) for the INTERVAL data type
Character	Description
`%%`	Identifies the % character.
`%n`	Identifies a newline character.
`%t`	Identifies a TAB character.