Good on MSWin32
----------------
%% '%' (%#% '%')
	A literal `%' character.
%a 'Sat' (%#a 'Sat')
	The abbreviated weekday name according to the current locale.
%A 'Saturday' (%#A 'Saturday')
	The full weekday name according to the current locale.
%B 'February' (%#B 'February')
	The full monthname according to the current locale.
%b 'Feb' (%#b 'Feb')
	The abbreviated month name according to the current locale.
%c '02/22/2003 12:03:45 AM' (%#c 'Saturday, February 22, 2003 12:03:45 AM')
	The preferred date and time representation for the current locale.
%d '22' (%#d '22')
	The day of the month as a decimal number (range 01 to 31).
%H '00' (%#H '0')
	The hour as a decimal number using a 24-hour clock (range 00 to
	23).
%I '12' (%#I '12')
	The hour as a decimal number using a 12-hour clock (range 01 to
	12).
%j '053' (%#j '53')
	The day of the year as a decimal number (range 001 to 366).
%m '02' (%#m '2')
	The month as a decimal number (range 01 to 12).
%M '03' (%#M '3')
	The minute as a decimal number (range 00 to 59).
%p 'AM' (%#p 'AM')
	Either `AM' or `PM' according to the given time value, or the
	corresponding strings for the current locale. Noon is treated as
	`pm'and midnight as `am'.
%S '45' (%#S '45')
	The second as a decimal number (range 00 to 61).
%U '07' (%#U '7')
	The week number of the current year as a decimal number, range 00
	to 53, starting with the first Sunday as the first day of week 01.
	See also %V and %W.
%W '07' (%#W '7')
	The week number of the current year as a decimal number, range 00
	to 53, starting with the first Monday as the first day of week 01.
%w '6' (%#w '6')
	The dayof the week as a decimal, range 0 to 6, Sunday being 0. See
	also %u.
%x '02/22/2003' (%#x 'Saturday, February 22, 2003')
	The preferred date representation for the current locale without
	the time.
%X '12:03:45 AM' (%#X '12:03:45 AM')
	The preferred time representation for the current locale without
	the date.
%Y '2003' (%#Y '2003')
	The year as a decimal number including the century.
%y '03' (%#y '3')
	The year as a decimal number without a century (range 00 to 99).
%z 'W. Europe Standard Time' (%#z 'W. Europe Standard Time')
	The time-zone as hour offset from GMT. Required to emit
	RFC822-conformant dates (using "%a, %d %b %Y %H:%M:%S %z"). (GNU)
%Z 'W. Europe Standard Time' (%#Z 'W. Europe Standard Time')
	The time zone or name or abbreviation.

Bad on MSWin32
----------------
 %+ %C %D %F %g %G %h %k %l %n %P %r %R %s %t %T %u %V