# LDC-E2704 — A precedent with no date

## What it means

A precedent is anchored in time: its date orders it against later
holdings, overrulings, and court ranks. A precedent with no date — or
with a value the compiler cannot read as a date — floats outside that
order, so nothing may follow or overrule it. The compiler refuses the
precedent until the date is written.

The fix gives the date as a temporal literal. Dates that run
backwards — an overruling earlier than the date it overrules — and
references to rules the package never declares fail under sibling shapes
of the same check.

## Example

```law
language "law.core" version "0.2";
package demo.diagnostics version "0.1.0";
namespace "urn:law:demo:diagnostics";

entity Case;
entity Item;
relation clear(c: Case, i: Item) kind empirical;
relation vague(c: Case, i: Item) kind empirical;
factors Deal {
for c: Case, i: Item;
domain clear(c, i), vague(c, i);
plaintiff clear;
defendant vague;
courts Alpha;
}
precedent P1 of Deal {
court Alpha;
plaintiff clear;
defendant vague;
outcome clear(c, i);
}
```

## Fix

```law
language "law.core" version "0.2";
package demo.diagnostics version "0.1.0";
namespace "urn:law:demo:diagnostics";

entity Case;
entity Item;
relation clear(c: Case, i: Item) kind empirical;
relation vague(c: Case, i: Item) kind empirical;
factors Deal {
for c: Case, i: Item;
domain clear(c, i), vague(c, i);
plaintiff clear;
defendant vague;
courts Alpha;
}
precedent P1 of Deal {
court Alpha;
decided @2020-01-01;
plaintiff clear;
defendant vague;
outcome clear(c, i);
}
```

## Engine message

The engine reports this in its own wording:

```text
example.law:16:11: error LDC-E2704: precedent P1: `decided` is required and is a date (§276.3/§276.6)
```

## Related

- [Facts and evidence](/constructs/facts-and-evidence/) — what an assertion carries.
- [Time](/constructs/time/) — how dates are written and read.