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Date

IANA permanent response RFC 9110 2 spellings

Declared by 50 providers across 3934 published specification files in the APIs.io network.

What this header is for, and how to use it →

A count here is providers whose published contract declares this header — not providers who send it. Response headers set at the edge rarely appear in an OpenAPI at all, so a low number can measure documentation practice rather than deployment.

Spelled 2 ways

HTTP field names are case-insensitive (RFC 9110 §5.1), so every spelling below is the same header on the wire. A contract is not the wire: generated clients key off the string, and a developer reading two of these sees two different headers.

Datedate

The registry

Statuspermanent
ReferenceRFC 9110, Section 6.6.1: HTTP Semantics

Providers declaring it (50)

adobe-suite aeropay aimlapi api-pulse apiops-cycles-canvas bird bitpowr-technologies-inc blnkfinance brightcove chaitin cisco-meraki cisco-secure-firewall cisco-umbrella citi conekta deliverect deluxe extreme-networks finix finix-payments fintecture hipay infisical interchecks kudosity lemlist linkedin london-stock-exchange-group messaging-api microsoft-azure mparticle nasuni orders-api persons-api products-api rhombus-systems salesforce satispay shopback shyft sofi-technologies streamelements tetrascience tribe-payments unified-to upwind userpilot vtex xflow zoominfo

Explore

All headers Representation Metadata Guidance on headers.apievangelist.com

Work with this as data

Every header here is available over the APIs.io API and to AI agents over MCP. HTTP Headers is not yet its own endpoint on the v1 API. Reach it through catalog search and the tag graph, or the MCP server.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for http headers

3 MCP tools reach this
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools →

Call it yourself

curl for this page
Search the catalog
curl "https://apis.io/api/v1/search?q=date&limit=10"
Everything under a tag
curl "https://apis.io/api/v1/tags/date"

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