Article thumbnail
Location of Repository

Why and how people of limited intelligence become calendrical calculators

By Richard Cowan, Neil O'Connor and Katerina Samella


Calendrical calculation is the rare talent of naming the days of the week for dates in the past and future. Calendrical savants are people with low measured intelligence who have this talent. This paper reviews evidence and speculation about why people become calendrical savants and how they answer date questions. Most savants are known to have intensively studied the calendar and show superior memory for calendrical information. As a result they may answer date questions either from recalling calendars or by using strategies that exploit calendrical regularities. While people of average or superior intelligence may become calendrical calculators through internalising formulae, the arithmetical demands of the formulae make them unlikely as bases for the talents of calendrical savants. We attempt to identify the methods used by a sample of 10 savants. None rely on an internalised formula. Some use strategies based on calendrical regularities probably in conjunction with memory for a range of years. For the rest a decision between use of regularities and recall of calendars cannot be made

Year: 2001
OAI identifier:

Suggested articles


  1. (1969). A further account of the idiots savants, experts with the calendar.
  2. (1971). A manual for the embedded figures test.
  3. (1975). An investigation of calendar calculating by an idiot savant.
  4. (1991). An investigation of the calendar calculation ability of a Chinese calendar savant.
  5. (1983). An islet of ability in autistic children: A research note. doi
  6. (1988). Another calendar savant.
  7. (1989). Autism: Explaining the enigma.
  8. (1995). Calendar calculating idiots savants and the smart unconscious. doi
  9. (1988). Calendar calculating in "idiots savants": How do they do it?
  10. (1965). Calendar calculation in a multiple-handicapped blind person.
  11. (1945). Case history of a so-called idiot savant.
  12. (1992). Do young calendrical calculators improve with age?
  13. (1989). Extraordinary people.
  14. (1989). Fragments of genius: The strange feats of idiots savants.
  15. (1983). Frames of mind: The theory of multiple intelligences.
  16. (1990). How to build a connectionist idiot (savant).
  17. (1965). Identical twin -"idiot savants"- calendar calculators.
  18. (1984). Idiot savant calendrical calculators: Maths or memory?
  19. (1986). Idiot savant calendrical calculators: Rules and regularities.
  20. (1977). Idiot savants: Rate of incidence.
  21. (1994). Lewis Carroll's formula for calendar calculating.
  22. (1997). Memory in the calendar calculating savant.
  23. (1989). Musical savants: Exceptional skill in the mentally retarded.
  24. (1999). Not just fun and games.
  25. (1981). Practical astronomy with your calculator. (2nd ed.). Cambridge:
  26. (1997). Questioning the millennium.
  27. (1978). Savant capabilities of autistic children and their cognitive implications.
  28. (1999). Savant syndrome-rhyme without reason. In
  29. (1978). Savants: Mentally retarded individuals with special skills. In
  30. (1991). Talents and preoccupations in idiot-savants.
  31. (1994). The "intelligence" of calendrical calculators.
  32. (1998). The arithmetical abilities of savant calendrical calculators. Manuscript submitted for publication.
  33. (1973). The digit span of idiots savants.
  34. (1985). The man who mistook his wife for a hat.
  35. (1887). To find the day of the week for any given date.
  36. (1994). Wechsler IQ profile and theory of mind in autism: A research note.
  37. (1988). What's exceptional about exceptional abilities ? In

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.