Definition
A preposition of spatial and temporal relation that, in legal contexts, carries a precise technical meaning distinct from its ordinary use. Courts and drafters have assigned "between" two principal legal functions:
1. Distance and boundary. When used to describe a span of space or distance, "between" excludes the two termini — the endpoints are not included within the range. A measurement or location described as lying "between" two fixed points does not include those points themselves.
2. Time computation. When used to define a period within which an act must be performed, "between" two named days excludes both days. An obligation to be performed "between Monday and Friday" must be completed after Monday has begun and before Friday commences — neither boundary day is available for performance. Courts have consistently held that both named days are excluded in this computation.
3. Reciprocal relation and shared ownership. "Between" also describes a mutual or bilateral relationship — something shared by, belonging to, or operating as between two parties. In property and contract drafting, this usage signals reciprocity or joint interest.
Common Language
Modern common usage (Wiktionary): Primarily a needle type in sewing contexts; in general English, "between" indicates the space or interval separating two things, or something shared by two parties.
Historical common usage (Webster's 1913): "In the space which separates; betwixt"; also "belonging in common to two; shared by both"; used for motion from one body or place to another.
The gap between common and legal meaning is narrow but operationally significant: ordinary usage of "between two dates" is often understood loosely to include those dates, or at least one of them. The legal rule is stricter — both termini are excluded. A drafter or researcher relying on common intuition about "between Monday and Friday" may reach the wrong conclusion about which days are available for performance.
Common Confusion
"Between" vs. "among." Ordinary grammar instruction teaches that "between" applies to two parties and "among" to three or more. Legal usage does not strictly follow this rule. Anderson's Dictionary of Law notes that "between" is often synonymous with "among" — particularly in distributions of property — and that it is equally appropriate to say property is divided "between" A, B, and C as "among" them. Researchers reading older deeds, wills, and distribution orders should not infer a two-party limitation simply from the appearance of "between."
Why It Matters in Research
The operational weight of "between" appears most often in three research contexts:
Time-computation disputes. Contract and statutory deadlines phrased with "between" have generated litigation over whether boundary days are included. The excluding-both-termini rule is well-established in American case law but is easy to overlook when reading instruments informally. Researchers analyzing deadline clauses, notice requirements, or performance windows in historical instruments should treat "between" as a signal to apply the exclusionary rule — both named days fall outside the permissible period.
Boundary and distance descriptions. In older deeds and survey language, "between" two monuments, roads, or landmarks excludes those markers from the described parcel. This matters in adverse possession, easement, and boundary dispute research, where the precise inclusion or exclusion of a terminus can shift the outcome.
Property distribution language. In wills, trust instruments, and partition orders, the "between"/"among" distinction is legally insignificant — courts have declined to limit distributions to two parties based on the word "between" alone. Researchers reading historical probate records should not treat "between" as evidence that only two beneficiaries were intended.
Jurisdictional variation in time rules is minimal — the excluding-both-termini reading is consistent across the American authorities — but the New Jersey materials cited in Black's suggest some variation at the margins. Where critical deadlines are at issue, check the controlling jurisdiction's treatment directly rather than assuming uniformity.
Historical Dictionary Support
Black's Law Dictionary (both editions) and Bouvier's Law Dictionary are in agreement on the core rule: as a measure of distance or time, "between" excludes the two termini. Both cite the same line of cases (Massachusetts, Maine, Illinois, Barbour's New York) with consistent results. Black's second edition adds the New Jersey case noting some qualification, suggesting the rule is not absolute and that context may occasionally permit a different reading.
Anderson's Dictionary of Law is the most useful source on the "between"/"among" equivalence question, citing Kentucky and Iowa authority for the proposition that no numerical limitation to two parties should be inferred from "between" in distribution contexts. This is a point the other historical dictionaries largely omit.
Bouvier adds the gloss that "between" as a preposition "primarily indicates" an intermediate position, which aligns with its spatial and temporal uses but does not fully account for its reciprocal-relation function. None of the historical dictionaries address the needle/sewing definition that appears in modern general dictionaries — that meaning is entirely unrelated to legal usage.
Jurisdictional Note
The excluding-both-termini rule for time computations is broadly consistent across American jurisdictions. Some statutory schemes now define "between" explicitly or incorporate day-counting rules that supersede common law interpretation; always check applicable rules of procedure or construction statutes when computing deadlines in litigation contexts.
Encyclopedia Cross-Reference
Equitable Conversion — Risk of Loss Between Contract and Closing (The Law Mind Real Estate Transactions & Construction Encyclopedia): directly engages the legal significance of time periods framed as "between" two events.
Marital Property — Debts and Liabilities (Allocation Between Spouses) (The Law Mind Family Law Encyclopedia): illustrates the reciprocal-relation usage of "between" in property division contexts.