Day, Month, Year, and Era Format Pictures

The format picture for a date string consists of a combination of null-terminated strings.

Day  
d Day of the month as digits without leading zeros for single digit days.
dd Day of the month as digits with leading zeros for single digit days
ddd Day of the week as a 3-letter abbreviation as given by a LOCALE_SABBREVDAYNAME value.
dddd Day of the week as given by a LOCALE_SDAYNAME value.
Month  
M Month as digits without leading zeros for single digit months.
MM Month as digits with leading zeros for single digit months
MMM Month as a three letter abbreviation as given by a LOCALE_SABBREVMONTHNAME value.
MMMM Month as given by a LOCALE_SMONTHNAME value.
Year  
y Year represented only be the last digit.
yy Year represented only be the last two digits.
yyyy Year represented by the full 4 digits.
Period/Era  
gg Period/era string as given by the CAL_SERASTRING value.

The "gg" format picture in a date string is ignored if there is no associated era string.