Calendar calculating savants with autism – how do they do it?

Savants with autism are people who exhibit an exceptional ability whilst also having social and cognitive impairments. One such ability is calendar calculating – being able to say, with astounding accuracy and alacrity, what day of the week a given date falls on. Just how some savants with autism are able to achieve this feat has baffled researchers. It’s been suggested that they use complex algorithms, but this seems implausible given that the same individuals often struggle with maths.

To help solve the mystery, Anna Dubischar-Krivec and colleagues recruited three savant calendar calculators with autism and pitted their calendrical skills against three neuro-typical calendar calculators recruited through a Swiss science TV show.

The participants were tested with questions that took the following form: “Is it true that 6 November 1974 = Thurs?”. The savants with autism beat the neuro-typical calendar experts, in terms of speed and accuracy, for past dates (these went back fifty years) and dates from the current month. By contrast, the performance of the two groups was matched for future dates, which were taken from up to fifty years ahead.

As usual, the savants were unable to say how they achieved their calendar skills. However, the researchers said the pattern of results implies that the savants were using different strategies from the neuro-typicals. Whereas the neuro-typicals relied on algorithms for past, present and future dates, the savants probably relied on rote memory for past and present dates, the researchers said, hence their superior speed and accuracy for these, whilst they probably fell back on some kind of algorithmic system for future dates.

These conclusions were supported by the fact that the savants’ answers seemed too quick, at least as regards dates in the current month (their average response time was less than three seconds), for them to have performed algorithmic calculations. Also they appeared to have made use of memory “anchor dates” based around the month of December, as betrayed by their reaction times tending to be quicker for months later and earlier in the year.

However, the mystery remains far from solved. For example, if the savants were relying on memory for their astonishing calendrical feats, you’d think a memory test would reveal their unusual memory ability. Yet a standard psychometric comparison of memory performance between the savant and neuro-typical calendar calculators found no differences, except the neuro-typicals were better on a form of working memory.

ResearchBlogging.orgDubischar-Krivec, A., Neumann, N., Poustka, F., Braun, C., Birbaumer, N., & Bölte, S. (2008). Calendar calculating in savants with autism and healthy calendar calculators. Psychological Medicine, 39 (08) DOI: 10.1017/S0033291708004601

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

18 thoughts on “Calendar calculating savants with autism – how do they do it?”

  1. I am convince that our brain has an amazing capacity, and it absorbs lots of information all the time, much more than what we think. IT might not even do models of things, what it iuses are just specialized filters

  2. “Calendar calculating in savants with autism and healthy calendar calculators.”

    Are you trying to imply that autistics have “unhealthy” brains?
    It is incredible, never mind totally offensive, that even when we outperform non-autistics we are the ones considered defective.

  3. Wow what an interesting read!

    I wonder if I might shoot a perhaps off-topic question your way but related in the sense of autism. I wonder what your take on the recovery movement hitting the mental health field is?

    I know there is a lot of debate on all sides, but I would very much love to hear anyone's opinion on the matter!

    If at all possible, I'd even like to quote them or reference them on my own blog, the Mental Health Recovery Blog if at all possible!

    If not I would love to hear the discourse here anyways!

    I look forward to speaking with you more in the future!!

    Warm regards,
    MHCD Research and Evaluations

  4. As a psychologist I worked with a person who could to the calendaring. However when I asked the date for something in 1610 he said he did not know. He mom said that was because he had not looked at it. This suggested it is a photographic type of memory. The person just pulls up the picture and looks at it.

  5. As parents of two autistic boys, we discovered this ability in one of our boys (Hamza, 9) a few days back. I saw this blog while trying to find more about this ability. last night we checked him for different dates from 1911 to 2045 and he took about a second to respond correctly. He is a high functioning autistic child with very good memory. His current pastimes include poring over the atlas and travel books. I was wondering what other abilities are usually associated with this one, so that we may be able work with him on those.
    Mukarram Ansari, pakistan

  6. Lex,

    I am wondering if you ever received an answer to your question or found any more research. I am searching for the answer of the same question myself and would love your feedback.

  7. I have a female friend that is completely normal that can do this. She's not sure what her range is because she hasn't checked. She also remembers every date she's ever been told. She can tell her sister, “Remember that boyfriend you had way back in Jr. High? It's his birthday tomorrow.” Adding large groups of numbers is another ability.

  8. My son is 8 and has autism (High functioning). He can calendar calculate but can only go back 50 years. When he was 5 he would sit and study the current year calendar and then his horizons expanded. When we explained how leap years worked (It is no tjust every 4 years as many people thing) he was very interested. He gave me a hint recently when I asked him to give the day of week for certain birthdays. For one that was back in the 60's he said “That's 2007” (I think I got the year right). Si it seems he has memorised the calendar for certain years and he must have a way of knowing which years relate to those memorised years. His interest in date and time extends to events. When he relates an even several years ago he can tell us the date and time, he used to always ask us about the current time and it seems he allocates a date/index for things in his memory. He remembers all sort of facts/ numbers and also street maps,he has the main routes of our city memorised and if you mention a suburb he can tell you what map square it is in. He has had a few street directories and when he gets a new one he is able to tell us of changes. He's also very good at Piano. Like one of the other posts I wonder what else it might indicate and what his future is.

  9. I discovered it independently back when I was ten with patterns in the celebdar depending on lengths of months and years and which centuries had leap years (Greg / Julian) calendar.

    Got to memorise 1 January for every year of 20th century and first day of 00 years for entire Commmon Era (easily calculable).

    Stephen Bishop
    Gunnedah, NSW

  10. My son is 6 and he has been day date calculating for 2-3 years. I think he literally sees the calendar in his head. You can almost see him flipping the pages. He has been reading for 3 years, his comprehension I'd limited only by his ability to construct sentences, tho he understands plenty. He can add, subtract, multiply and divide. He can count by any number, 2,3,5,even 59 if you want. He thought himself the Greek alphabet. He is gifted at seeing patterns. He is funny, has a fantastic sense of humor and lives people. He may be behind playdates on play skills, but he loves them just the same.

  11. My son is 7, autistic and can tell days for the years 2013 years past and 10000 years in future. And has has not seen all the calendars. I believe he calculates somehow

    1. i think u shoul contact an expert in astro physics something bcoz looking into 10000yrs ahead is rare, plus he is verbal so can tell

  12. I was googling something unrelated to this topic but this blog page was amid the results and happened to catch my eye. I thought it was an interesting read. I doubt very many (if anyone) will read my reply but I will leave it nonetheless in case somebody may happen along and find it useful. I am diagnosed with aspergers disorder. I have an average IQ but with significant subtest/index scatter. I have been doing “calendar calculation” since childhood. I have unusual arithmetic calculation skills. I have an unusual memory for numbers. Nothing in nature is free however, some aspects of my memory are below 10th percentile.

    I can't speak for anyone else because we're all different, so I'll tell you what a calendar is like for me. It 'feels' like a series of repeating patterns that twit around each other somewhat similar to strands of DNA. As I follow a pattern there is a feeling of motion like water shifting back and forth in a container. I use the word “feeling” loosely because it is closer to a phantom feeling such as amputees report. To me it seems that it is mathematical calculation but an alternative system of math. And I think this is why it seems like mystery to people.

    You might ask why someone would want to do calendar calculation, because it doesn't have any practical uses. Again, I can't speak for anyone else. For me it just feels good. It's relaxing. Simple as that. Maybe a mental form of rocking? I don't know.

  13. I understand. I just started “doing” this as an Aspie and I find it extremely enjoyable. I can't get enough of it. With me it's like wheels spinning in my brain and then the outcome. I can do 1700 to 2200 but after that it's like a wall.

  14. My 11 years old son with high functioning autism has always been able to do that. He learned to read by himself, he is very good at finding patterns and is good at maths. He also remembers very precisely the date of everything he did (for example, if he sees a drawing he did 5 years ago, he knows exactly the date he draw it). When I ask him how he knows, for example, that April 15, 2011 is a Friday, he tells me that he sees the calendar in his head. What is strange is that he is not very interested in calendars and does not spend time studying them at all. He knows by heart all the genealogy of the kings of France, but this is something that interest him more.

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