date_trunc

The date function used to truncate a date or datetime value to the start of a given unit of duration. Takes two arguments, the date to truncate and the unit of duration (one of "year", "decade", "century", "quarter", "month", "week", "day", "hour", "minute", "second", or "millisecond"). The function returns a value of the same type as it's first argument.

Returns: any

PREFIX : <https://ddw-doccorp.linked.data.world/d/sparql-function-sample-queries/>
PREFIX fn: <http://data.world/function/functions#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>

SELECT (fn:date_trunc("2001-03-15"^^xsd:date, "month") as ?date_diff)
{
}