query: #Whose birthday is it today with a round number. e.g: 10, 20, 30 or 130 years
  SELECT ?birthdayboy ?birthdayboyLabel (YEAR(?date) AS ?year) ?date ?age WHERE {
    BIND(MONTH(NOW()) AS ?nowMonth)
    BIND(DAY(NOW()) AS ?nowDay)
    ?birthdayboy wdt:P569 ?date.
    BIND(YEAR(?date) AS ?year)
    BIND(((YEAR(NOW())) - ?year) / 10 AS ?decade)
    BIND(ROUND(((YEAR(NOW())) - ?year) / 10) AS ?decaderounded)
    BIND(?decade * 10 AS ?age)
    SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
    FILTER(?decade = ?decaderounded)
    FILTER(((MONTH(?date)) = ?nowMonth) && ((DAY(?date)) = ?nowDay))
  }