Circa date range

Discussion in 'English Only' started by Pupuhd, Sep 8, 2011.

  1. Pupuhd New Member

    I have a good idea as to how and when to use circa to approximate dates. I even read that one meaning of circa would be +- 10 years.

    I am restoring a vintage air compressor which after it is complete will have three separate components from three different manufactures with three different manufactured dates. I want to create a plate on the final restoration with my name, restoration year and manufacture, model number and manufactured date for each of the three components.

    My question here is: how would I correctly circa date, lets say the electric motor, if so far the only research tells me in was made in the early 1960's. If I follow the above rule of just indicating "Manufactured Date: c. 1960", that would indicate anything from the 50' to the 70's. This specification would be incorrect because the 50's motor was different in design from the 60's and the 70's.

    How would I correctly display this on the restoration plate so the viewer would have a better understanding of manufactured date?


    Thank you, David
  2. PaulQ

    PaulQ Senior Member

    English - England
    1. Surely it will be "Manufacture date" not "Manufactured date"
    2. An apostrophe is not used with dates.

    "Manufacture date: c. 1960" or "Manufacture date: early 1960s" or "Manufacture date: mid-1960s"

    However you could have (no colon)

    "Manufactured circa 1960" or "Manufactured early 1960s" or "Manufactured mid-1960s"

    One or two of these should work.
  3. JulianStuart

    JulianStuart Senior Member

    Sonoma County CA
    English (UK then US)
    I don't know where you read about the +/- 10 years but it is by no means standard as a range. Stonehenge was started c. 3500 BC but that certainly does not mean between 3490 and 3510 BC!I would say c. 1960 would be vague enough yet still informative enough, but have no idea of whether the people who might read this plate would have their own "rules/conventions" about the precision required! It does capture your current uncertainty!
  4. natkretep

    natkretep Moderato con anima (English Only)

    English (Singapore/UK), basic Chinese
    Welcome to the forum, David!

    I haven't heard of circa meaning ±10 years. I've always just understood it to mean around, as in John Horsley, archaeologist (born c. 1685). I haven't seen c. used with a range, so your second and third options look strange to me. At the moment, I prefer the first option.
  5. exgerman Senior Member

    English but my first language was German
    Circa indicates a rounded number. For dates, you are specifying that the actual date is probably in the range that rounds to the number you are giving. In your example, the range 1956-1965 rounds to 1960, because 1955 would round down to 1950, and 1966 would round up to 1970.

    This is obviously not an absolute rule. If there are other indications of the rounding range, they would override the default expected range. Also, the range for century dates, 50-year dates (1950) and quarter-century dates (1975) might extend further than 10 years, depending on context.

    I would assume that natcretep's example also is intended to indicate a range centered on 1685. If the writer thought that a date before 1680 or after 1690 were as likely as a date in the range 1680-1689, he would have expressed himself differently.

    In short, a 10-year range for a circa date is a reasonable inference unless there are indications that the author intends a different range.

    In your case, I'd say early 1960s, because you know that a more exact dating is possible.

    About the apostrophe: many people do use an apostrophe in 1960's, and it drives professional writers crazy. If you use the apostrophe, be prepared for people who overlook your motor but want to talk to you about the apostrophe.
    Last edited: Sep 8, 2011
  6. Pupuhd New Member


    I don't hang around people who would even discuss the apostrophe.:p

    I found this in, but no reference to follow up on:
    "Circa means "around" or "about". If the exact date of an event is uncertain, "circa" may be used to indicate that the date is somewhere within about 10 years of the "circa" year given. ex. He was born circa 1820. (This means that the birth date was somewhere between 1810 and 1830.)"

    While all known references don't mention the +-10 years, I just want to get more information on this subject as I continue the restoration. Thanks-David

    As far as Manufacture or Manufactured is irrelevant. The brass etched restoration plate would only have the word DATE etched into the brass. There will be a non-etched box next to it for information to be stamped into it.

    Even though I haven't completed the research so far I can only assume it was built in the early 1960's. Feedback at other forum regarding this motor indicated that they know of the ones they had to be between 1964-1965. However, cannot rule out they were only built through out those years. So with that said and until my research indicates differently, I might think best if it stated one the following:

    DATE C.1960'S
    DATE C. EARLY 1960
    DATE C. EARLY 1960'S

    The stamp set only have one font style and all capitalized.

    Thanks, David
    Last edited: Sep 8, 2011
  7. JulianStuart

    JulianStuart Senior Member

    Sonoma County CA
    English (UK then US)

    I'm sorry but I disagree - although I agree with you when you do say it's not an absolute rule! I don't go along with the "rounding", and in any case I round 1955 up to 1960, consistent with all my mathematical and scientific training. There is likely a relationship between the precision a number implies and the magnitude of the uncertainty associated with it but that should be presented as e.g. c. 1850 is more precise than mid-19th century.

    I recommend putting the best estimate as the number and leaving the degree of uncertainty as , well, uncertain :D If your best research indicates somewhere near 1964, but you are not sure, then " c. 1964 " represents your information.
  8. Pupuhd New Member

    I may have to agree on this point. Even though my research is not yet completed, so far the only dates I've received are 1964-1968 (not 1964-1965 as stated earlier). Going with the above conclusion I can safely make the restoration plate as follow:

    DATE C.1965

    This would put the circa date midrange in the decade based on the information gathered so far. Thanks, David.

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