static Long ai_englishToDate(S s) {
  ret ai_englishToDate(s, now());
}

static Long ai_englishToDate(S s, long now) {
  if "today|now" ret now;
  if "yesterday" ret now()-daysToMS(1);
  if "the day before yesterday" ret now()-daysToMS(2);
  if "tomorrow" ret now()+daysToMS(1);
  if "the day after tomorrow" ret now()+daysToMS(2);
  null;
}