support %Z, %c, %x, %X, %P. fix %p, %F. split i18n
add date/dayOfTheYear
fix date/strftime %j and reuse date/dayOfTheYear
add date/timezoneOffset
reuse date/timezoneOffset on date/strftime
add date/timezoneAbbr
reuse date/timezoneAbbr in date/strftime
fix strftime "%c" spec
add date/weekOfTheYear
add support for %U and %W on strftime