var hour, minute, second, amPm []byte               // Parsing result will be here

digits := WhileAcceptable(span.Range('0', '9'))     // Allow only bytes in the range '0'..'9'
twoDigits := RequireLen(2, digits)                  // Require the sequence to be 2 bytes in length
time24 := Sequence(
  Take(into.Bytes(&hour), twoDigits),               // Parse hour and write the result in `hour`
  Expect(':'),                                      // Expect ':' after the hour
  Take(into.Bytes(&minute), twoDigits),             // Parse minute and write the result in `minute`
  Optional(                                         // Parse optional second
    Expect(':'),                                    // Expect ':' after the the minute
    Take(into.Bytes(&second), twoDigits),           // Parse second and write the result in `second`
  ),
)
time12 := Sequence(
  time24,                                           // Extend 24-hour time parser
  Optional(While(' ')),                             // Skip optional whitespace
  Take(                                             // Parse AM/PM part
    into.Bytes(&amPm),                              // On success write the result in `amPm`
    ExpectAcceptable(span.Set('a', 'A', 'p', 'P')), // Expect one byte from the set aApP
    ExpectAcceptable(span.Set('m', 'M')),           // Expect one byte from the set mM
  ),
)

timeBite := NewBite(Switch(time12, time24))         // Wrap parsers into the bynom.Eater.
if err := dish.NewString(inputData); err != nil {
  panic(err)
} else {
  println(string(hour), ":", string(minute), ":", string(second), " ", string(amPm))
}