{
  "name": "hour",
  "type": "function",
  "groups": ["Date and Time"],
  "description": "Extracts the hour part from a datetime or time, or the number of hours from an interval.",
  "variants": [{
    "variant": "Time variant",
    "variant_description": "Extracts the hour part from a time or datetime.",
    "arguments": [{
      "arg": "datetime",
      "description": "a time or datetime value"
    }],
    "examples": [{
      "expression": "hour( to_datetime('2012-07-22 13:24:57') )",
      "returns": "13"
    }]
  }, {
    "variant": "Interval variant",
    "variant_description": "Calculates the length in hours of an interval.",
    "arguments": [{
      "arg": "interval",
      "description": "interval value to return number of hours from"
    }],
    "examples": [{
      "expression": "hour(to_interval('3 hours'))",
      "returns": "3"
    }, {
      "expression": "hour(age('2012-07-22T13:00:00','2012-07-22T10:00:00'))",
      "returns": "3"
    }, {
      "expression": "hour(age('2012-01-01','2010-01-01'))",
      "returns": "17520"
    }]
  }],
  "tags": ["extracts", "number", "time", "part", "interval", "hours", "hour", "datetime"]
}