Date Regex

gistfile1.rb

date = '03/27/1992'

year = /(?<year>(20)?(07|08|09|10|11|12))/
month = /(?<month>0[1-9]|1[012])/
day = /(?<day>0[1-9]|\.[1-9]|[12][0-9]|3[01])/
NUMERAL_DATE_REGEX = /#{year}(?<separator>\.|\-|\/|_)?#{month}(\k<separator>)?#{day}/

if match = NUMERAL_DATE_REGEX.match(@file_name)
  Date.parse(date).strftime("%y.%m.%d")
end