QGIS/resources/function_help/json/to_interval

{
  "name": "to_interval",
  "type": "function",
  "groups": ["Conversions", "Date and Time"],
  "description": "Converts a string to an interval type. Can be used to take days, hours, month, etc of a date.",
  "arguments": [ {"arg":"string","description":"a string representing an interval. Allowable formats include {n} days {n} hours {n} months."}],
  "examples": [
    { "expression":"to_interval('1 day 2 hours')", "returns":"interval: 1.08333 days"},
    { "expression":"to_interval( '0.5 hours' )", "returns":"interval: 30 minutes"},
    { "expression":"to_datetime('2012-05-05 12:00:00') - to_interval('1 day 2 hours')", "returns":"2012-05-04T10:00:00"}
  ]
}