---
title: "dbt models with several dates and no default | Metacenta"
description: "A table with order_date, shipped_at and settled_ts gives three answers to \"revenue by month\". Why AI agents guess wrong, and which description fixes it."
url: "https://metacenta.com/rules/model-date-ambiguous"
updated: "2026-10-14"
tokens: 647
---

Documentation · rule model-date-ambiguous

# dbt models with several dates and no default

A Metacenta review checks this under the rule **Core models with several dates say which is which**. Everything below applies whether or not you ever commission one.

## What this rule checks

This rule looks at each core model that declares two or more date columns. It flags the model when none of those dates has a description. A model counts as core when a dbt exposure, Looker explore or Tableau view depends on it. If none is declared, the marts count instead. A column counts as a date by its type, or by a name such as `_date`, `_at` or `_ts`.

## Why it matters

A total by month needs one date. With three undescribed dates, a person asks which one is meant; an AI agent picks one. Two picks give two totals for the same month, and both look right.

## How to fix it

**Say which date each main table reports by.** Describe each date column: the event it records and its time zone. Say which date is the default for reporting, so a reader who needs one knows where to start.

Before:

```yaml
    columns:
      - name: order_date
      - name: shipped_at
      - name: settled_ts
```

After:

```yaml
    columns:
      - name: order_date
        description: Date the customer placed the order (UTC). Report revenue by this.
      - name: shipped_at
        description: When the parcel left the warehouse (UTC).
      - name: settled_ts
        description: When the payment provider settled the charge (UTC).
```

## When it is fine to leave

One described date is enough to pass, because a reader then has a default. Audit timestamps such as `_loaded_at` can stay undescribed if the reporting date is described.

## What we need to check it

`manifest.json`. Consumers come from exposures in the manifest, or from LookML or Tableau files if you share them. A date found by its name is medium confidence; one typed as a date is high.

[Ask about a review](https://metacenta.com/enquire?src=rule-model-date-ambiguous&via=md)

## Related pages

- [dbt models with no description](https://metacenta.com/rules/model-undocumented)
- [dbt columns with no description](https://metacenta.com/rules/model-columns-undocumented)
- [dbt models that declare no columns](https://metacenta.com/rules/model-no-column-schema)
- [dbt sources with no description](https://metacenta.com/rules/source-undocumented)
- [A sample review, as a client reads it](https://metacenta.com/sample)
- [All published rules](https://metacenta.com/rules)
- [How a review is assessed](https://metacenta.com/standard)