{"id":"cron-describe-fields","version":"1.0.0","description":"Parse a five-field cron expression and return each field’s expanded numeric values and wildcard status.","supported_operations":["describe cron fields","explain a cron expression","expand cron numeric values","show cron minute and hour sets","parse cron schedule fields","understand what a cron means"],"unsupported_operations":["compute run times","translate cron to natural language prose","named months or weekdays"],"semantics":["Vixie wildcard status is true when a field starts with *, including */n; if either day field starts with *, both day value sets must match; otherwise day matching uses OR.","Returns five fields in POSIX.1-2024 crontab utility INPUT FILES section order.","Vixie cron 3.0pl1 lists, ranges, and steps expand to sorted unique integers; weekday 7 normalizes to 0."],"limits":{"max_input_bytes":512,"max_expression_bytes":128,"max_field_items":60,"max_output_bytes":4096},"pricing":{"status":"unpriced","charge_usd":null},"input_schema":{"type":"object","additionalProperties":false,"required":["expression"],"properties":{"expression":{"type":"string","minLength":1,"maxLength":128}}},"output_schema":{"type":"object","additionalProperties":false,"required":["expression","fields","standard_version"],"properties":{"expression":{"type":"string","minLength":1,"maxLength":128},"fields":{"type":"array","minItems":5,"maxItems":5,"items":{"type":"object","additionalProperties":false,"required":["name","source","wildcard","values"],"properties":{"name":{"type":"string","enum":["minute","hour","day_of_month","month","day_of_week"]},"source":{"type":"string"},"wildcard":{"type":"boolean"},"values":{"type":"array","minItems":1,"maxItems":60,"items":{"type":"integer"}}}}},"standard_version":{"type":"string","const":"POSIX.1-2024 crontab utility, INPUT FILES"}}},"examples":[{"input":{"expression":"0 9 * * 1-5"},"output":{"expression":"0 9 * * 1-5","fields":[{"name":"minute","source":"0","wildcard":false,"values":[0]},{"name":"hour","source":"9","wildcard":false,"values":[9]},{"name":"day_of_month","source":"*","wildcard":true,"values":[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31]},{"name":"month","source":"*","wildcard":true,"values":[1,2,3,4,5,6,7,8,9,10,11,12]},{"name":"day_of_week","source":"1-5","wildcard":false,"values":[1,2,3,4,5]}],"standard_version":"POSIX.1-2024 crontab utility, INPUT FILES"}},{"input":{"expression":"*/20 * * * *"},"output":{"expression":"*/20 * * * *","fields":[{"name":"minute","source":"*/20","wildcard":true,"values":[0,20,40]},{"name":"hour","source":"*","wildcard":true,"values":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23]},{"name":"day_of_month","source":"*","wildcard":true,"values":[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31]},{"name":"month","source":"*","wildcard":true,"values":[1,2,3,4,5,6,7,8,9,10,11,12]},{"name":"day_of_week","source":"*","wildcard":true,"values":[0,1,2,3,4,5,6]}],"standard_version":"POSIX.1-2024 crontab utility, INPUT FILES"}}],"execute_url":"/v1/tools/cron-describe-fields/versions/1.0.0/execute"}