A QUO

Definition

Latin: "from which." A phrase used in legal writing to mark the starting boundary of a computation — whether of time or of distance. It designates the point of origin in a range, as distinguished from its counterpart, ad quem ("to which"), which marks the endpoint. The phrase appears most often in three related constructions: 1. Dies a quo — the day from which a period of time begins to run. Used in statutes of limitations, notice requirements, appeal deadlines, and any other time computation where the trigger date must be identified. 2. Terminus a quo — the point or limit from which a measurement of distance or a legal passage begins. Used in surveying, boundary disputes, and jurisdictional descriptions. 3. Court a quo — the court from which a case was appealed or removed. A reviewing court refers to the lower tribunal as "the court a quo," identifying it as the originating forum.

Common Confusion

A quo is sometimes confused with its correlative ad quem without attention to which term does which work. A quo is always the starting point; ad quem is always the endpoint. In deadline computation, the distinction is critical: the dies a quo may or may not be counted as day one depending on the applicable rule (many jurisdictions exclude the triggering day from the count). Researchers should not assume that identifying the dies a quo resolves the computation — the counting rule is a separate question.

Why It Matters in Research

The phrase appears throughout older case law, treatises, and appellate opinions in ways that modern sources often translate loosely or omit. When reading historical opinions, particularly in equity, civil procedure, or appellate jurisdiction, a quo will signal a structural argument about which court had authority, or where a time period began. The "court a quo" usage is the most common surviving form in American legal writing and remains active in appellate opinions. A researcher encountering "the court a quo" in a brief or opinion should read it simply as "the lower court" or "the originating court" — but the phrase also carries implicit framing: it signals the reviewing court's perspective, looking back toward the tribunal below. In deadline and limitations research, dies a quo is the older formulation for what modern statutes more commonly address by specifying whether the triggering event is "included" or "excluded" from the count. Older cases using dies a quo may not map neatly onto modern computation rules; the underlying common law default (generally excluding the first day) may differ from current statutory or rule-based defaults in the relevant jurisdiction. Distance-based uses (terminus a quo in surveying or boundary contexts) appear in older land records and colonial-era deeds and are rare in modern litigation but surface in historical title research.

Historical Dictionary Support

Black's (1st and 2nd editions) and Burrill's are in close agreement. All three sources define a quo as "from which" and pair it immediately with ad quem as its correlative. Burrill explicitly cross-references "Dies a quo" and "From" as companion entries, signaling that the phrase was understood as part of a family of related locutions rather than a standalone term. Both editions of Black's present the same illustrative pairings — dies a quo / dies ad quem and terminus a quo / terminus ad quem — suggesting these compound forms were the primary contexts in which courts and practitioners actually deployed the term. None of the historical sources address the "court a quo" usage directly under this entry, though that application was well established in practice by the time these dictionaries were published. Researchers should not read the omission as evidence that the court-designation usage was uncommon; it was simply treated as self-evident from the base meaning.

Jurisdictional Note

Deadline computation rules governing the dies a quo vary by jurisdiction and by the source of the rule (common law, statute, court rule). Federal courts follow Federal Rule of Civil Procedure 6, which generally excludes the triggering day; state rules differ. The Latin phrase itself is neutral on this question.

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