date

Type: coerce

Signature: md.coerce.date({ output: 'iso' })

What It Is

md.coerce.date({ output: 'iso' }) coerces loose values into a strict ISO datetime parse and returns a normalized ISO string. The schema combines operators such as document(), section(), fields(), and date() to map 1 h2 section and list content into top-level keys meta for this coerce date behavior. When constraints are broken, issue codes like missing_section identify exactly which date node failed and why.

When to Use

Choose md.coerce.date({ output: 'iso' }) when source values may arrive loosely typed but the stored contract still needs a strict ISO string result. Skip it when consumers want a Date instance directly, because md.coerce.date() or md.date() is a better fit. Combining it with document(), section(), fields(), and date() yields predictable date parsing, clearer errors, and easier runtime integration.

Input Markdown

## 1. META

- StartAt: 2026-03-10T12:00:00.000Z

Schema

import { md } from '@markschema/mdshape'

const schema = md.document({
  meta: md.section('1. META').fields({
    StartAt: md.coerce.date({ output: 'iso' }),
  }),
})

Result

Success

{
  "success": true,
  "data": {
    "meta": {
      "StartAt": "2026-03-10T12:00:00.000Z"
    }
  }
}

Error

Failure trigger: The input violates one or more constraints declared in the schema; use issues[].path and issues[].code to locate the exact failing node.

{
  "success": false,
  "error": {
    "issues": [
      {
        "code": "missing_section",
        "message": "Missing section \"1. META\"",
        "path": [
          "meta"
        ],
        "line": 1,
        "position": {
          "start": {
            "line": 1,
            "column": 1
          }
        }
      }
    ]
  }
}

Additional Scenarios

coerce + pipeline hardening

Input Markdown

## 1. META

- Score: 8

Schema

import { md } from '@markschema/mdshape'

const schema = md.document({
  meta: md.section('1. META').fields({
    Score: md.coerce.number().pipeline(md.number().int().min(0).max(10)),
  }),
})

Result

Success

{
  "success": true,
  "data": {
    "meta": {
      "Score": 8
    }
  }
}

Error

Failure trigger: The input violates one or more constraints declared in the schema; use issues[].path and issues[].code to locate the exact failing node.

{
  "success": false,
  "error": {
    "issues": [
      {
        "code": "missing_section",
        "message": "Missing section \"1. META\"",
        "path": [
          "meta"
        ],
        "line": 1,
        "position": {
          "start": {
            "line": 1,
            "column": 1
          }
        }
      }
    ]
  }
}