{"uid":"cap_Jx1yr2bmwxyUAzy62501J","slug":"calendar-systems-solstice-equinox-moments-f9218167","name":"Calendar Systems – Solstice & Equinox Moments","description":"March and September equinox and June and December solstice moments (UTC) for a year, with season lengths in days.","url":"https://calendar-systems.x402tookit.com/seasons?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["year"],"properties":{"year":{"type":"integer","description":"Gregorian year, 1900 to 2100"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"asOf":{"type":["null","string"]},"year":{"type":["null","number"]},"source":{"type":["null","string"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"summary":{"type":["null","string"]},"verdict":{"type":["null","string"]},"accuracy":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"disclaimer":{"type":["null","string"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"juneSolstice":{"type":["null","string"]},"marchEquinox":{"type":["null","string"]},"seasonStarts":{"type":["array","null"],"items":{"type":"object","properties":{"utc":{"type":["null","string"]},"event":{"type":["null","string"]},"begins":{"type":["null","string"]}}}},"juneSolsticeJd":{"type":["null","number"]},"marchEquinoxJd":{"type":["null","number"]},"decemberSolstice":{"type":["null","string"]},"septemberEquinox":{"type":["null","string"]},"seasonLengthsDays":{"type":["null","object"],"properties":{"fromJuneSolstice":{"type":["null","number"]},"fromMarchEquinox":{"type":["null","number"]},"fromDecemberSolstice":{"type":["null","number"]},"fromSeptemberEquinox":{"type":["null","number"]}}},"decemberSolsticeJd":{"type":["null","number"]},"septemberEquinoxJd":{"type":["null","number"]}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_QYn0lpvkuaE3xsWthWVns","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the exact UTC moments of the March equinox, June solstice, September equinox, and December solstice for any Gregorian year from 1900 to 2100, along with season lengths in days.","exampleAgentPrompt":"What are the exact UTC times of the March equinox, June solstice, September equinox, and December solstice for 2025, and how long is each season in days?","exampleUseCases":[{"title":"Seasonal campaign planning for 2026","prompt":"Can you give me the precise UTC times for all four solstices and equinoxes in 2026, plus how many days each season lasts? I want to time our marketing campaigns around the astronomical seasons."},{"title":"Astronomy app event scheduling","prompt":"I need the exact moment — down to the minute in UTC — when each of the four solstices and equinoxes occurs in 2027, including their Julian Day Numbers, for an astronomy event calendar I'm building."},{"title":"Comparing season lengths across years","prompt":"How long is each astronomical season in days for the year 2000? I want to compare the season lengths to those in 2050 to study how they shift over time."}],"resultDescription":"A JSON object containing the UTC datetime strings and Julian Day Numbers for all four seasonal turning points (March equinox, June solstice, September equinox, December solstice) for the requested year, plus an object with season lengths in days measured from each event, along with metadata fields like source, accuracy, and any degraded-service flags.","failureModes":["Year outside the supported 1900–2100 range returns an error or null results","Missing required 'year' query parameter causes a validation error","Degraded service flag set to true if computation is approximate or data source is unavailable","Non-integer year value rejected by schema validation"],"whenToPreferThis":"Choose this endpoint when you need precise astronomical UTC timestamps (and Julian Day Numbers) for all four seasonal turning points in a single call for any year between 1900 and 2100. Prefer it over general astronomy APIs when you also need season lengths in days and a lightweight, cheap per-call pricing model without authentication overhead.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T00:30:47.010Z","isFirstParty":false,"canonicalSlug":"calendar-systems-solstice-equinox-moments-f9218167"}