# `MishkaDocument.Resources.Calculations.LastModified`
[🔗](https://github.com/mishka-group/mishka_document/blob/v0.0.1/lib/mishka_document/resources/__calculations/last_modified.ex#L5)

When a section — one page of a document — last changed: the newest of its own `updated_at`, the
`updated_at` of the notes its page shows (approved, not archived) and the time a note was
archived, which takes the note off the page. A section with no notes keeps its own.

The sitemap's `lastmod`, the page's `dateModified` and `doc.modified_at`, and the "Updated" line
under the page's title read this one value. Notes are read as part of the section's own query
(`latest_note_change_at` and `latest_note_archived_at`), so a batch of sections is one read, and
nothing is written to a section when a note changes.

    calculate :last_modified_at, :utc_datetime_usec, LastModified

# `describe`

# `has_calculate?`

# `has_expression?`

# `init`

# `strict_loads?`

---

*Consult [api-reference.md](api-reference.md) for complete listing*