The following formatting characters can be used for date and time formatting: 

d  Represents the day of the month as a number from 1 through 31. A singledigit day is formatted without a leading zero. 
dd  Represents the day of the month as a number from 01 through 31. A singledigit day is formatted with a leading zero. 
ddd  Represents the abbreviated name of the day of the week: "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", and "Sat". 
dddd (plus any number of additional "d" specifiers)  Represents the full name of the day of the week: "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", and "Saturday". 
f  Represents the most significant digit of the seconds fraction. 
ff  Represents the two most significant digits of the seconds fraction. 
fff  Represents the three most significant digits of the seconds fraction. 
ffff  Represents the four most significant digits of the seconds fraction. 
fffff  Represents the five most significant digits of the seconds fraction. 
ffffff  Represents the six most significant digits of the seconds fraction. 
fffffff  Represents the seven most significant digits of the seconds fraction. 
F  Represents the most significant digit of the seconds fraction. Nothing is displayed if the digit is zero. 
FF  Represents the two most significant digits of the seconds fraction. However, trailing zeros, or two zero digits, are not displayed. 
FFF  Represents the three most significant digits of the seconds fraction. However, trailing zeros, or three zero digits, are not displayed. 
FFFF  Represents the four most significant digits of the seconds fraction. However, trailing zeros, or four zero digits, are not displayed. 
FFFFF  Represents the five most significant digits of the seconds fraction. However, trailing zeros, or five zero digits, are not displayed. 
FFFFFF  Represents the six most significant digits of the seconds fraction. However, trailing zeros, or six zero digits, are not displayed. 
FFFFFFF  Represents the seven most significant digits of the seconds fraction. However, trailing zeros, or seven zero digits, are not displayed. 
g or gg (plus any number of additional "g" specifiers)  Represents the period or era (A.D. for example). This specifier is ignored if the date to be formatted does not have an associated period or era string. 
h  Represents the hour as a number from 1 through 12, that is, the hour as represented by a 12hour clock that counts the whole hours since midnight or noon. Consequently, a particular hour after midnight is indistinguishable from the same hour after noon. The hour is not rounded, and a singledigit hour is formatted without a leading zero. For example, given a time of 5:43, this format specifier displays "5". 
hh, hh (plus any number of additional "h" specifiers)  Represents the hour as a number from 01 through 12, that is, the hour as represented by a 12hour clock that counts the whole hours since midnight or noon. Consequently, a particular hour after midnight is indistinguishable from the same hour after noon. The hour is not rounded, and a singledigit hour is formatted with a leading zero. For example, given a time of 5:43, this format specifier displays "05". 
H  Represents the hour as a number from 0 through 23, that is, the hour as represented by a zerobased 24hour clock that counts the hours since midnight. A singledigit hour is formatted without a leading zero. 
HH, HH (plus any number of additional "H" specifiers)  Represents the hour as a number from 00 through 23, that is, the hour as represented by a zerobased 24hour clock that counts the hours since midnight. A singledigit hour is formatted with a leading zero. 
m  Represents the minute as a number from 0 through 59. The minute represents whole minutes passed since the last hour. A singledigit minute is formatted without a leading zero. 
mm, mm (plus any number of additional "m" specifiers)  Represents the minute as a number from 00 through 59. The minute represents whole minutes passed since the last hour. A singledigit minute is formatted with a leading zero. 
M  Represents the month as a number from 1 through 12. A singledigit month is formatted without a leading zero. 
MM  Represents the month as a number from 01 through 12. A singledigit month is formatted with a leading zero. 
MMM  Represents the abbreviated name of the month: "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov" and "Dec". 
MMMM  Represents the full name of the month: "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November" and "December". 
s  Represents the seconds as a number from 0 through 59. The second represents whole seconds passed since the last minute. A singledigit second is formatted without a leading zero. 
ss, ss (plus any number of additional "s" specifiers)  Represents the seconds as a number from 00 through 59. The second represents whole seconds passed since the last minute. A singledigit second is formatted with a leading zero. 
t  Represents the first character of the A.M./P.M. designator. The A.M. designator is used if the hour in the time being formatted is less than 12; otherwise, the P.M. designator is used. 
tt, tt (plus any number of additional "t" specifiers)  Represents the A.M./P.M. designator. The A.M. designator is used if the hour in the time being formatted is less than 12; otherwise, the P.M. designator is used. 
y  Represents the year as at most a twodigit number. If the year has more than two digits, only the two loworder digits appear in the result. If the year has fewer than two digits, the number is formatted without a leading zero. 
yy  Represents the year as a twodigit number. If the year has more than two digits, only the two loworder digits appear in the result. If the year has fewer than two digits, the number is padded with leading zeroes to achieve two digits. 
yyy  Represents the year as a threedigit number. If the year has more than three digits, only the three loworder digits appear in the result. If the year has fewer than three digits, the number is padded with leading zeroes to achieve three digits.
Note that for the Thai Buddhist calendar, which can have fivedigit years, this format specifier displays all five digits. 
yyyy  Represents the year as a fourdigit number. If the year has more than four digits, only the four loworder digits appear in the result. If the year has fewer than four digits, the number is padded with leading zeroes to achieve four digits.
Note that for the Thai Buddhist calendar, which can have fivedigit years, this format specifier renders all five digits. 
yyyyy (plus any number of additional "y" specifiers)  Represents the year as a fivedigit number. If the year has more than five digits, only the five loworder digits appear in the result. If the year has fewer than five digits, the number is padded with leading zeroes to achieve five digits.
If there are additional "y" specifiers, the number is padded with as many leading zeroes as necessary to achieve the number of "y" specifiers. 
z  Represents the signed time zone offset of your system from Greenwich Mean Time (GMT) measured in hours. For example, the offset for a computer in the Pacific Standard Time zone is "8".
The offset is always displayed with a leading sign. A plus sign (+) indicates hours ahead of GMT and a minus sign () indicates hours behind GMT. The offset ranges from 12 through +13. A singledigit offset is formatted without a leading zero. The offset is affected by daylight savings time. 
zz  Represents the signed time zone offset of your system from Greenwich Mean Time (GMT) measured in hours. For example, the offset for a computer in the Pacific Standard Time zone is "08".
The offset is always displayed with a leading sign. A plus sign (+) indicates hours ahead of GMT and a minus sign () indicates hours behind GMT. The offset ranges from 12 through +13. A singledigit offset is formatted with a leading zero. The offset is affected by daylight savings time. 
zzz, zzz (plus any number of additional "z" specifiers)  Represents the signed time zone offset of your system from Greenwich Mean Time (GMT) measured in hours and minutes. For example, the offset for a computer in the Pacific Standard Time zone is "08:00".
The offset is always displayed with a leading sign. A plus sign (+) indicates hours ahead of GMT and a minus sign () indicates hours behind GMT. The offset ranges from 12 through +13. A singledigit offset is formatted with a leading zero. The offset is affected by daylight savings time. 
:  The time separator. 
/  The date separator. 
"  Quoted string (quotation mark). Displays the literal value of any string between two quotation marks ("). 
'  Quoted string (apostrophe). Displays the literal value of any string between two apostrophe (') characters. 
\c  The escape character. Displays the character "c" as a literal when that character is preceded by the escape character (\). 
Any other character  Any other character is copied to the result string, and does not affect formatting. 