ymd           = fromGregorian                   <$> year  <* sep <*> month <* sep <*> day  <* eof :: Parser Date
ymd           = fromGregorian                   <$> year  <* sep <*> month <* sep <*> day  <* eof :: Parser Date
ymd           = fromGregorian                   <$> year  <* sep <*> month <* sep <*> day  <* eof :: Parser Date