{"uid":"cap_rjvpUvo1EsXPiwPvVXN8d","slug":"keyronne-datetime-conversion-arithmetic-api-3e9abb53","name":"Keyronne Datetime Conversion & Arithmetic API","description":"The timezone conversions and date arithmetic LLMs get wrong, done exactly. Convert any ISO timestamp or Unix time into one or many IANA timezones (with UTC offset and weekday), add or subtract durations, and diff two instants into days/hours/minutes plus a humanized string. Omit \"datetime\" to get the current time. Uses the IANA timezone database. POST a JSON body like: {\"datetime\":\"2026-07-08T14:30:00Z\",\"timezone\":\"America/New_York\"}","url":"https://keyronne.com/api/datetime?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"add":{"type":"object","properties":{"unit":{"enum":["ms","seconds","minutes","hours","days","weeks"],"type":"string"},"amount":{"type":"number"}},"description":"Add a duration (negative amount subtracts)."},"until":{"description":"Another datetime; returns the difference from \"datetime\" to this."},"datetime":{"description":"ISO 8601 string or Unix timestamp (seconds or millis). Defaults to now."},"timezone":{"type":"string","description":"IANA timezone for the result, e.g. \"Asia/Tokyo\". Default UTC."},"timezones":{"type":"array","items":{"type":"string"},"description":"Convert into several zones at once."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","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":{"p10Cents":"0.1000","medianCents":"0.1000","p90Cents":"0.1000","minCents":"0.1000","maxCents":"0.1000","p95Cents":"0.1000","sampleCount":1,"varies":false,"failureChargeRate":1},"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_7KsEsbJ0YgNvHNCRCh4vA","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Converts ISO or Unix timestamps across IANA timezones, adds/subtracts durations, and diffs two instants with humanized output — or returns current time if no datetime is supplied.","exampleAgentPrompt":"What time will 2026-07-08T14:30:00Z be in America/New_York and Asia/Tokyo, and what day of the week does it land on?","exampleUseCases":null,"resultDescription":"Returns the input datetime converted into the requested IANA timezone(s) with UTC offset and weekday name; if 'add' was specified, returns the resulting datetime after the duration is applied; if 'until' was specified, returns the difference between the two instants in days, hours, and minutes plus a humanized string like '3 days and 4 hours'. Omitting 'datetime' returns the current time.","failureModes":["Invalid IANA timezone name returns an error indicating unrecognized zone","Malformed ISO 8601 string or non-numeric Unix timestamp returns a parse error","Missing required fields with incompatible combinations (e.g. 'until' with no base datetime) may return a validation error","Network or server errors return HTTP 5xx","Insufficient USDC balance or x402 payment failure blocks the request"],"whenToPreferThis":"Use this endpoint whenever precise, authoritative timezone conversion or date arithmetic is needed — especially to avoid LLM hallucinations on DST transitions, UTC offsets, or day-of-week calculations. Prefer it over LLM reasoning for any time math involving real IANA zones, duration addition/subtraction, or computing intervals between two timestamps.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-11T00:43:50.504Z","isFirstParty":false,"canonicalSlug":"keyronne-datetime-conversion-arithmetic-api-3e9abb53"}