An anniversary is the date on which an event took place or an institution was founded in a previous year, and may also refer to the commemoration or celebration of that event. For example, the first event is the initial occurrence or, if planned, the inaugural of the event. One year later would be the first anniversary of that event. The word was first used for Catholic feasts to commemorate saints.
Most countries celebrate national anniversaries, typically called national days. These could be the date of independence of the nation or the adoption of a new constitution or form of government. The important dates in a sitting monarch's reign may also be commemorated, an event often referred to as a "jubilee".
The Latin phrase dies natalis (literally "birth day") has become a common term, adopted in many languages, especially in intellectual and institutional circles, for the anniversary of the founding ("legal or statutory birth") of an institution, such as an alma mater (college or other school). In ancient Rome, the [dies] Aquilae natalis was the "birthday of the eagle", the anniversary of the official founding of a legion.
Anniversaries of nations are usually marked by the number of years elapsed, expressed with Latin words or Roman numerals.
Latin terms for anniversaries are mostly straightforward, particularly those relating to the first twenty years (1–20), or multiples of ten years (30, 40, 60, 70 etc.), or multiples of centuries or millennia (100, 200, 300, 1000, 2000, 3000, etc.) In these instances, the name of the anniversary is generally derived from the Latin word(s) for the respective number of years. However, when anniversaries relate to fractions of centuries (125, 150, 175, 250 years—i.e. 1.25, 1.5, 1.75, and 2.5 centuries), the situation is not as simple.
Roman fractions were based on a duodecimal system. From 1⁄12 to 8⁄12 they were expressed as multiples of twelfths (uncia "twelfth"; the source of the English words inch and ounce) and from 9⁄12 to 11⁄12 they were expressed as multiple twelfths less than the next whole unit—i.e. a whole unit less 3⁄12, 2⁄12 or 1⁄12 respectively. There were also special terms for quarter (quadrans), half (semis), and three-quarters (dodrans). Dodrans is a Latin contraction of de-quadrans which means "a whole unit less a quarter" (de means "from"; quadrans means "quarter". Thus for the example of 175 years, the term is a quarter century less than the next whole (bi)century or 175 = (−25 + 200).
In Latin, it seems that this rule did not apply precisely for 1½. While secundus is Latin for "second", and bis for "twice", these terms are not used such as in sesqui-secundus. Instead sesqui (or ses) is used by itself.
|Anniversary||Latin-derived term||Other terms||Comments|
|20 years||Vigintennial / Vicennial||China/Porcelain|
|25 years||Quadranscentennial||Silver jubilee|
|40 years||Quadragennial||Ruby jubilee|
|50 years||Semicentennial / Quinquagenary||Golden jubilee|
|60 years||Sexagennial / Sexagenary||Diamond jubilee|
|65 years||Sapphire jubilee|
|70 years||Septuagennial||Platinum jubilee|
|125 years||Quasquicentennial||Term is broken down as quasqui- (and a quarter) centennial (100 years). Quasqui is a contraction from quadrans "a quarter" plus the clitic conjunction -que "and". The term was coined by Funk and Wagnalls editor Robert L. Chapman in 1961.|
|150 years||Sesquicentennial||Term broken down as sesqui- (one and a half) centennial (100 years)|
|175 years||Dodransbicentennial||Dodrans is a Latin contraction of de-quadrans which means "a whole unit less a quarter" (de means "from"; quadrans means "quarter"). 175 years is a quarter century less than the next whole (bi)century or 175 = (−25 + 200).|
|Dodrabicentennial||Alternative Latin form of Dodransbicentennial|
|Dequasbicentennial||Alternative Latin form of Dodransbicentennial|
|Dosquicentennial||Dosquicentennial has been used in modern times and this is perhaps a modern contraction of "de-quadrans". However, it seems inappropriate to combine the terms que and de when dealing with such Roman fractions. In any event, if such a conjunction was appropriate then it would perhaps more likely have been "Dosquibicentennial" (but the result is little shorter anyway).|
|Demisemiseptcentennial||Probably a modern coined term: demisemiseptcentennial; literally one-half (demi-) × one-half (semi-) × seven (sept-) × 100 years (centennial)—also demisemiseptcentenary.|
|Quartoseptcentennial||Probably a modern coined term: quartoseptcentennial; literally one-quarter (quarto-) × seven (sept-) × 100 years (centennial)—also quartoseptcentenary.|
|Terquasquicentennial||First used by Bell Laboratories in celebrating its 175th anniversary as a corporation. Is a coined word for an anniversary of 175 years, but the elements of the word literally refer to an anniversary of 375 years, as follows: ter- (3) × quasqui- (1¼) × centennial (100 years)|
|Suggested by lexicographer Robert L. Chapman to William Safire; first appeared in Safire's column, "On Language" (The New York Times Magazine, February 12, 1995). It is a coined word for an anniversary of 175 years, but the elements of the word literally refer to an anniversary of 35,000 years, as follows: septaquinta- (70) × quinque- (5) × centennial (100 years)|
|250 years||Sestercentennial||-||To express 2½ in Latin it would be expressed as "half-three". The term relates to being halfway [from the second] to the third integer. In Latin this is "Sestertius" which is a contraction of semis (halfway) tertius (third)—hence Sestercentennial.|
|Semiquincentennial||Probably a modern coined term: semi- (half) × quin (5) × centennial (100 years) = 250 years. Used by Brown University in 2015.|
|Bicenquinquagenary||Used by Princeton University in 1996, Reading, Pennsylvania in 1998, and Washington and Lee University in 1999. It is a coined word for an anniversary of 250 years: bi- (2) × cen(t)- (100) + quinquagenary (50 years).|
|Quarter-millennial||Meaning one quarter of one thousand years.|
|300 years||Tercentenary / Tricentenary||Tercentennial / Tricentennial|
|350 years||Sesquarcentennial||A modern coined term; sesquarcentennial for 350 years is deduced here from the "Sestertius" definition for 250 years above. For 350 years it relates to being halfway from the third to the fourth integer; thus a contraction of semis (halfway) and quartus (fourth); hence Sesquarcentennial.|
|Semiseptcentennial||Probably a modern coined term: semi- (half) × sept(7) × cen(t)- (100) × centennial (350 years)|
|400 years||Quadricentennial||Quadricentenary / Quatercentenary|
|700 years||Septcentennial||Septuacentennial||Probably a coined term; earliest known use in March 1988. Chiang Mai Septcentennial Stadium (Chiang Mai, Thailand) was completed in 1991.|
|1500 years||Sesquimillennial||Term broken down as sesqui- (one and a half) millennial (1000 years)|
Many anniversaries have special names. Etiquette in Society, in Business, in Politics and at Home by Emily Post, published in 1922, contained suggestions for wedding anniversary gifts for 1, 5, 10, 15, 20, 25, 50, and 75 years. Wedding anniversary gift suggestions for other years were added in later editions and publications; they now comprise what is referred to as the "traditional" list. Generally speaking, the longer the period, the more precious or durable the material associated with it. See wedding anniversary for a general list of the wedding anniversary symbols; however, there are variations in some national traditions.
Furthermore, there exist numerous partially overlapping, partially contradictory lists of anniversary gifts (such as wedding stones), separate from the 'traditional' names.
So the name for a 175th anniversary? For now it is really up to the preference of the reader. One day one of these terms may make its way into popular usage, become accepted, and find a place in a dictionary.
It is our policy to reply as courteously and helpfully as we can to such requests, and I answered Mr. Hatten on August 7, suggesting quasquicentennial. Since this is a history, I shall quote the letter in full: Dr. Wilfred Funk has passed your letter of July I on to us. We are happy to help, if you feel that you really want a new Latinate word meaning "one hundred and twenty-fifth anniversary". The best model upon which to form the word is "sesquicentennial", meaning "one hundred and fiftieth anniversary". We need a first element meaning "plus a fourth", analogous with "sesqui" which means "plus a half". "Sesqui" is apparently formed from "semis que", meaning "and a half". Now, both "quarta" and "quadrans" mean "a fourth", so we may begin with either "quarta que" or "quadrans que". The trick is to combine and shorten one of these as "sesqui" was combined and shortened from "semis que". If we follow the model of "sesqui" very closely, retaining the stressed vowel and final "s" of "quadrans", we get the word "quasquicentennial". Combining and shortening in other ways we can also get "quadqui-", "quansqui-", "quarsqui-", and perhaps several others. On the grounds that it is closest to the model and also probably the least ugly of the set, I would choose "quasquicentennial" (pronounced kwahskwee-) as the new word. Of course, you may decide that you do not really want or need a new word. There is no point in proliferating them needlessly. I should add, perhaps, that this word would not appear in any of our dictionaries until it had established itself in wide currency, even if you should decide to use it. I hope we have been able to help you.
The etymology of "demisemiseptcentennial" is compared to "hemidemisemiquaver", a 64th note.
Faster, it seems, than you can say "bicenquinquagenary", Princeton's 250th anniversary has come and gone.