Definition
A phrase used in legal instruments, pleadings, affidavits, and indictments to approximate a date or time without committing to a precise statement. By inserting "on or about" before a date, the drafter acknowledges that the exact date may not be known or verifiable and disclaims strict reliance on the stated date as an element of the claim or charge.
The phrase performs two related functions depending on context:
1. In criminal pleadings and indictments, "on or about" signals that the prosecution is not bound to prove the offense occurred on the exact date alleged, provided the actual date falls within the applicable statute of limitations and is not so remote as to surprise or prejudice the defendant.
2. In conveyancing and civil instruments, "on or about" protects a recital from failure if the referenced document turns out to bear a slightly different date than stated. A deed described as dated "on or about" a given date remains admissible to support title even if the precise date is mistaken.
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Common Language
Modern common usage (Wiktionary): approximately.
Historical common usage (Webster's 1913): Webster's 1913 does not carry a separate entry for this phrase; "about" is defined as "near to in time, quantity, number, degree," with "on or about" functioning in ordinary speech as a casual approximation.
The gap between common and legal usage is procedural rather than semantic. In everyday speech, "on or about" is a loose synonym for "approximately" with no legal consequence. In legal documents and pleadings, the phrase is a term of art that activates specific rules: it defines the scope of variance a party may rely upon between what was alleged and what the evidence proves, and it determines whether a variance between pleading and proof is fatal. A non-lawyer reading "on or about" in a contract or indictment may assume it is simply informal hedging, when in fact it has formal doctrinal effect.
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Common Confusion
"On or about" is sometimes confused with mere careless drafting or vagueness. In fact, its use in an indictment is a deliberate and accepted practice, not a defect. A defendant who challenges an indictment for lack of specificity because it uses "on or about" rather than a precise date will typically fail, because courts recognize the phrase as a standard approximation device that does not deprive the defendant of fair notice so long as the timeframe is otherwise reasonable. The phrase should not be confused with a bill of particulars request—if a defendant genuinely needs a more specific date, the remedy is a motion for a bill of particulars, not a challenge to the "on or about" language itself.
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Why It Matters in Research
The phrase appears across vastly different legal contexts—criminal indictments, civil complaints, conveyancing recitals, affidavits, and contract instruments—and its operative effect differs in each. Researchers reading historical sources must distinguish between the conveyancing rule (where "on or about" protects a recital from strict date-matching) and the pleading rule (where it governs the permissible variance between allegation and proof at trial). Burrill's entry speaks almost exclusively to the conveyancing context; modern criminal procedure doctrine on variance is not captured by any of the historical dictionaries in this corpus.
In criminal law research, the key question is how much variance is tolerable between the date alleged "on or about" and the date proved at trial. Historical sources are silent on this because the modern variance doctrine developed largely through twentieth-century case law. Researchers working on indictment sufficiency, statute of limitations questions, or double jeopardy analysis (where the date of offense affects whether two charges are the same act) should not rely on the historical dictionary definitions alone—they address a narrower drafting question, not the full procedural doctrine.
In civil and transactional research, the phrase signals that a recital is not a warranty of date accuracy. Researchers tracing title chains or interpreting instrument references in historical deeds should note that a deed recited as dated "on or about" a certain date may carry a different execution or recording date; this is a feature, not a defect, under the conveyancing practice Burrill describes.
Jurisdictional variation in criminal pleading tolerance for "on or about" language is modest—the phrase is widely accepted across American jurisdictions—but the permissible span of variance and the interaction with statute of limitations periods can differ. Researchers working on historical prosecutions should check the jurisdiction's pleading rules, as some states impose greater specificity requirements by rule or statute.
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Historical Dictionary Support
The historical sources agree on the core function of the phrase: it is a device to avoid being bound by a precisely stated date. Burrill provides the most operationally useful explanation, connecting the phrase explicitly to conveyancing practice and identifying the evidentiary benefit—a deed described with "on or about" remains produceable in evidence despite a date error. Rapalje & Lawrence adds that the phrase appears in affidavits and other instruments as well, and flags a related construct, "on or before," with citations to specific contexts (bonds, covenants, promissory notes, marine insurance policies). Black's, both editions, and Bouvier's are brief and consistent, treating the phrase as a standard approximation tool without elaboration.
What the historical sources collectively miss is the criminal pleading dimension, which is now the phrase's most common legal context for modern practitioners and researchers. None of the dictionary entries addresses variance doctrine, the statute of limitations interplay, or double jeopardy implications. This omission reflects the relatively later development of detailed criminal procedure doctrine and the historical dictionaries' orientation toward civil and transactional law.
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Jurisdictional Note
The phrase is accepted in criminal indictments and civil pleadings across American and English jurisdictions without meaningful variation in its basic function. However, the degree of temporal variance tolerated between an "on or about" allegation and proof at trial varies by jurisdiction and is governed by rule, statute, and case law rather than by the phrase itself. Researchers should consult jurisdiction-specific pleading rules when the exact date of an offense is legally significant, as in cases involving limitations periods, sentencing enhancements tied to the date of conduct, or multi-count indictments where date specificity affects double jeopardy analysis.
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