What happens when I hit the request limit?

Requests over the limit return HTTP 429 with headers showing your standing, and are not counted against you. The counter resets at midnight UTC.

Pricing

Q: Is the holiday data accurate?

Data is sourced from open calendar projects, checked against independent references before each release, and organized with curated weekend rules and market calendars. Out-of-range requests return an error, never a guess.

Month to month, cancel whenever. Limits are requests per UTC day and reset at midnight. Every plan gets the full API and the widget library; the tiers differ in volume and how fast we answer.

Trying it

free

100 requests / day

Every endpoint included
Widgets, publishable key
100 calls a day, forever

developer

$8/mo

1,000 requests / day

Side project, graduated
Email support
Widgets in production

In production

Recommended

starter

$20/mo

10,000 requests / day

Production applications with steady traffic
Batch calls: one request per hundred operations
Email support, one business day

pro

$48/mo

100,000 requests / day

Widgets drop the "Powered by Dierum" badge
1,000-operation batches, priority support
Most teams start on Starter. The ones who shouldn't, usually know.

At scale

business

$150/mo

500,000 requests / day

Platforms, ETL, reconciliation runs
Priority support queue
Half a million calls a day of headroom

enterprise

$500+/mo

negotiated limits

Custom limits and contract terms
Invoicing and procurement-friendly
SLAs negotiated to your needs

Talk to us

Create a free key

Email. The key is tied to this address and shown once

Site origins (optional, adds a widget-ready publishable key)

Lost keys aren't recoverable (we store only a hash), but your account page can rotate and manage them any time.

Upgrade

Email on your existing key

Plan

Checkout and card handling are Stripe's, on their servers. We never see the number. Cancel any time; access drops to the free tier at period end.

Questions a careful buyer asks

What happens when I hit the limit?

429, with headers telling you where you stand. Over-limit requests aren't billed against your count. At midnight UTC the counter resets and requests flow again.

Is the data actually right?

It is sourced from open calendar projects, checked against independent references before each release, and organized with curated weekend rules and market calendars on top. The dataset version is public at /health. When a calculation would leave the covered range we return an error rather than a wrong answer.