shipapis
StarSubmit an APISubmit API

Public Time API vs The Calendar

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

APIPublic Time APIHEALTHY97The CalendarHEALTHY93
Uptime · 30d
Uptime · 90d99.44%100%
Uptime · 30d98.3%100%
P50 · ms311395
P95 · ms4493282
Authnonenone
CORSnoyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified (US federal list per 5 U.S.C. § 6103)
Free tierFree — limits not publishedFree, no auth (per site)
Rate limitRetry-After: 1020sNone stated (site advertises no rate limit)
In directory since2026-07-052026-07-05
operationalpartialdownno data

Public Time API vs The Calendar: common questions

Which is more reliable, Public Time API or The Calendar?

On our scheduled checks, The Calendar leads on measured uptime — Public Time API at 99.44% versus The Calendar at 100% over 90 days. These are our own probe results, not provider claims; the uptime bars above show the day-by-day record for both.

Which is faster, Public Time API or The Calendar?

Public Time API has the lower median latency in our checks — Public Time API responds in 311 ms versus The Calendar at 395 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 Public Time API and The Calendar need an API key?

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

Can I call Public Time API and The Calendar from the browser?

Only The Calendar is browser-friendly — it returns CORS headers over HTTPS. Public Time API needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are Public Time API and The Calendar free for commercial use?

Public Time API has unclear commercial terms, and The Calendar 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.