{"id":"iso-datetime-truncate","version":"1.0.0","description":"Truncate a strict UTC ISO-8601 datetime toward UTC zero at day, hour, minute, or second.","supported_operations":["iso datetime truncate","truncate utc datetime","floor iso datetime to unit"],"unsupported_operations":["round or ceil","truncate to week, month, or year","leap seconds","time zones","offsets other than Z","fractional seconds","locale","DST"],"semantics":["datetime must match YYYY-MM-DDTHH:MM:SSZ with zero-padded fields and a real proleptic Gregorian UTC civil time.","Years are 0001-9999. Days are linear 86400-second POSIX days. There are no leap seconds, fractional seconds, space separators, or offsets other than Z.","unit must be exactly day, hour, minute, or second.","Truncation zeros smaller fields toward UTC zero: day to T00:00:00Z, hour to HH:00:00Z, minute to HH:MM:00Z, second is identity.","The result is formatted YYYY-MM-DDTHH:MM:SSZ and stays on the same calendar date as the input."],"limits":{"min_year":1,"max_year":9999,"units":["day","hour","minute","second"]},"pricing":{"status":"unpriced","charge_usd":null},"input_schema":{"type":"object","additionalProperties":false,"required":["datetime","unit"],"properties":{"datetime":{"type":"string","minLength":20,"maxLength":20,"pattern":"^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}Z$"},"unit":{"type":"string","enum":["day","hour","minute","second"]}}},"output_schema":{"type":"object","additionalProperties":false,"required":["datetime"],"properties":{"datetime":{"type":"string","minLength":20,"maxLength":20,"pattern":"^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}Z$"}}},"examples":[{"input":{"datetime":"2026-09-11T12:34:56Z","unit":"hour"},"output":{"datetime":"2026-09-11T12:00:00Z"}}],"execute_url":"/v1/tools/iso-datetime-truncate/versions/1.0.0/execute"}