QML Time counter.qml

import QtQuick 2.12
import QtQuick.Window 2.12

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")

    Text {
        id: counter
        property int value: 0
        text: Math.floor(value / 60).toString()
              + ":"
              + ((value % 60) < 10 ? "0" : "")
              + (value % 60).toString()
    }

    NumberAnimation {
        id: counterAnim

        function begin(n) {
            from = n
            duration = n * 1000
            start()
        }

        target: counter
        property: "value"
        to: 0
    }
    MouseArea{
        anchors.fill: parent
        onClicked: counterAnim.begin(70)
    }
}