Recurrence in realtime.
Built for developers who demand precision. Fully RFC5545 compliant recurrence rule processing with sub-millisecond response times. Simple API, beautiful results.
TRY IT OUT
Build and test recurrence rules in real-time. See exactly how RFC5545 rules generate occurrence patterns.
Rule Builder
FREQ=WEEKLY;COUNT=10
curl -X POST https://demo.recurrence.dev/v1/expand \ -H "Content-Type: application/json" \ -d '{"rrule": "FREQ=WEEKLY;COUNT=10", "dtstart": "2026-01-05T09:00:00Z"}'
Occurrences
Select options and results will appear automatically
// Results will appear here
BUILT TO PERFORM
Stop reinventing recurrence rules. Get it right the first time.
100% RFC5545
Complete implementation of the iCalendar recurrence specification. Every edge case handled.
Sub-Millisecond
Optimized engine with typical response times under 1ms. Built for high-throughput applications.
Simple API
RESTful endpoints. Integrate with any language or platform.
Timezone Native
Full IANA timezone support. Handle DST transitions correctly.
Infinite Series
Efficiently handle unbounded recurrence rules with lazy evaluation.
Battle Tested
Comprehensive test suite against the RFC5545 specification.
SIMPLE PRICING
Start free. Scale as you grow.
Free
For side projects and testing
- 1,000 API calls/month
- Full RFC5545 support
- No streaming
Pro
For growing applications
- 25,000 API calls/month
- Full RFC5545 support
- Streaming API
Growth
For production workloads
- 50,000 API calls/month
- Full RFC5545 support
- Streaming API
Enterprise
For high-volume applications
- Unlimited API calls
- Streaming API
- Dedicated support
All plans include full RFC5545 compliance, timezone support, and sub-millisecond response times.
READY TO START?
Get your API key in seconds. Start building with a reliable RFC5545 recurrence engine.