#datetime

Work with ISO-8601 durations — the PnYnMnDTnHnMnS strings (P3Y6M4DT12H30M5S, PT1H30M) used across calendars, scheduling, video metadata, billing periods and APIs. Parse a duration into its components and a total in seconds and milliseconds; format a number of seconds (or individual year/month/week/day/hour/minute/second fields) back into a canonical ISO-8601 string; humanise any duration into readable text ("1 hour and 30 minutes"); and measure the exact duration between two instants (ISO timestamps or unix epochs) as both an ISO-8601 string and a precise second count. Years and months use documented calendar averages and are clearly flagged as approximate. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 5 endpoints. Distinct from date/time parsing and relative-time ("3 hours ago") formatting.

api.oanor.com/duration-api

A fast, fully-local date and time toolkit (UTC): parse any date string or unix timestamp into ISO, unix and components with the ISO week number, day-of-year and leap-year flag; format dates with custom tokens (YYYY-MM-DD, weekday and month names, and more); add or subtract month-aware durations; compute the difference between two dates in every unit plus a human-readable summary; and convert between unix timestamps and ISO. Every endpoint accepts input via the query string or the request body. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for scheduling, billing periods, reminders, analytics and any date arithmetic. (For the current time in a specific timezone, see the oanor Time API.)

api.oanor.com/datetime-api