Date/Time format strings control the conversion of strings into date-time type.
Date Time Format Strings are composed of specifies that describe values to be converted into the date-time value.
In the following table, specifies are given in the lower case. The case is ignored in formats, except for the "am/pm" and "a/p" specifies.
d Day as a number without a leading zero (1-31).
dd Day as a number with a leading zero (01-31).
m Month as a number without a leading zero (1-12).
mm Month as a number with a leading zero (01-12).
mmm Month as an abbreviation (Jan-Dec).
mmmm Month as a full name (January-December).
yy Year as a two-digit number (00-99).
yyyy Year as a four-digit number (0000-9999).
h Hour without a leading zero (0-23).
hh Hour with a leading zero (00-23).
n Minute without a leading zero (0-59).
nn Minute with a leading zero (00-59).
s Second without a leading zero (0-59).
ss Second with a leading zero (00-59).
zzz Fraction of Second with a leading zero (000-999).
(Works only for Oracle timestamp fields)
tt Uses the 12-hour clock for the preceding h or hh specifier, 'am' for any hour before noon, and 'pm' for any hour afternoon.