{"id":"iso-date-add","version":"1.0.0","description":"Add a signed whole-day delta to a strict YYYY-MM-DD calendar date.","supported_operations":["iso date add","add days to date","date plus days"],"unsupported_operations":["timezones","weeks","months","locale","Date local time"],"semantics":["Date must match /^[0-9]{4}-[0-9]{2}-[0-9]{2}$/ and be a real proleptic Gregorian calendar day with year 0001..9999.","Leap years: year % 4 == 0 && (year % 100 != 0 || year % 400 == 0). 0000 is not in range. 2000-02-29 valid, 1900-02-29 invalid, 2023-02-29 invalid.","days is a canonical integer string (same integer rules) whose BigInt absolute value is <= 3652425.","Do not use JavaScript Date for year 0-99 pitfalls. Use integer day counts (Rata Die or equivalent) in UTC civil calendar with no time-of-day.","Result must remain in 0001-01-01 .. 9999-12-31 or reject."],"limits":{"year_min":1,"year_max":9999,"max_abs_day_delta":3652425},"pricing":{"status":"unpriced","charge_usd":null},"input_schema":{"type":"object","additionalProperties":false,"required":["date","days"],"properties":{"date":{"type":"string","minLength":10,"maxLength":10},"days":{"type":"string","minLength":1,"maxLength":257}}},"output_schema":{"type":"object","additionalProperties":false,"required":["date"],"properties":{"date":{"type":"string","minLength":10,"maxLength":10}}},"examples":[{"input":{"date":"2026-09-10","days":"1"},"output":{"date":"2026-09-11"}},{"input":{"date":"2024-02-28","days":"1"},"output":{"date":"2024-02-29"}},{"input":{"date":"2024-03-01","days":"-1"},"output":{"date":"2024-02-29"}}],"execute_url":"/v1/tools/iso-date-add/versions/1.0.0/execute"}