# LDC-E1334 — Term duration in a wrong unit

## What it means

A term measures time in deadline units only: business days, calendar
days, weeks, months, or years — or a declared quantity binder the rule
binds. Any other unit, or a name that denotes no quantity binder,
cannot be added to a date, so the compiler stops at the duration.

The repair is to spell a deadline unit, or to bind the quantity the
duration should follow. A duration the calendar understands lowers
exactly as written.

## Example

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

entity Tenant;
relation moved_in(t: Tenant, day: Date) kind empirical;
relation rent_due(t: Tenant, day: Date) kind institutional;
term RentTerm {
    for t: Tenant;
    for day: Date;
    from moved_in(t, day);
    due rent_due(t);
    default 1 fortnight;
}
```

## Fix

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

entity Tenant;
relation moved_in(t: Tenant, day: Date) kind empirical;
relation rent_due(t: Tenant, day: Date) kind institutional;
term RentTerm {
    for t: Tenant;
    for day: Date;
    from moved_in(t, day);
    due rent_due(t);
    default 1 calendar_month;
}
```

## Engine message

The engine reports this in its own wording:

```text
example.law:13:15: error LDC-E1334: term "RentTerm": duration unit "fortnight" is not a §86 deadline unit
```

## Related

- [Deadlines and calendar](/constructs/deadline-calendar/) — durations and the units time is counted in.
- [Time](/constructs/time/) — dates and how terms anchor to them.