{
  "function": "day",
  "description": "Extract the day from a date, or the number of days from an interval.",
  "variants": [
  { "variant": "Date variant",
      "variant_description": "Extract the day from a date or datetime.",
      "arguments": [ {"arg":"date","description":"a date or datetime value"}],
      "examples": [ { "expression":"day('2012-05-12')", "returns":"12"}] },
      {
      "variant": "Interval variant",
      "variant_description": "Calculate the length in days of an interval.",
      "arguments": [ {"arg":"interval","description":"interval value to return number of days from"}],
      "examples": [ { "expression":"day(tointerval('3 days'))", "returns":"3"},
                    { "expression":"day(age('2012-01-01','2010-01-01'))", "returns":"730"}]
  }]
}