The Calendar vs TimeZones iCal Library

Same instrument, two spec sheets — measured, not claimed.

Uptime · 30d
Uptime · 90d100%100%
Uptime · 30d100%100%
P50 · ms588337
P95 · ms3550714
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverified (US federal list per 5 U.S.C. § 6103)Unverified
Free tierFree, no auth (per site)Free — limits not published
Rate limitNone stated (site advertises no rate limit)Unpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

The Calendar vs TimeZones iCal Library: common questions

Which is more reliable, The Calendar or TimeZones iCal Library?

Both are neck-and-neck — The Calendar and TimeZones iCal Library each measure 100% uptime over 90 days on our probe schedule. Reliability here is verified from our own scheduled checks; use the 30-day bars above to see which has been steadier lately.

Which is faster, The Calendar or TimeZones iCal Library?

TimeZones iCal Library has the lower median latency in our checks — The Calendar responds in 588 ms versus TimeZones iCal Library at 337 ms (P50). Tail latency (P95) is in the table above; for most workloads the median is the number that shapes how the API feels.

Do The Calendar and TimeZones iCal Library need an API key?

Neither needs a paid key — The Calendar is callable with no signup, and TimeZones iCal Library is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call The Calendar and TimeZones iCal Library from the browser?

Yes — both The Calendar and TimeZones iCal Library send CORS headers over HTTPS, so front-end code can fetch either directly with no backend proxy. That makes them easy to swap in a client-side app while you compare responses.

Are The Calendar and TimeZones iCal Library free for commercial use?

The Calendar has unclear commercial terms, and TimeZones iCal Library has unclear commercial terms. We track service terms and the data license as separate fields — see the Commercial use and Data license rows above, and confirm both before shipping either in a paid product.