$('table').tablesorter({
    widthFixed: true,
    // sort on the last name in ascending order
    sortList: [
        [2, 0]
    ],
    dateFormat: "ddmmyyyy",
    emptyTo: "zero",
    sortInitialOrder: "desc",
    headers: {
        3: {
            sorter: "shortDate"
        },
        4: {
            sorter: "shortDate"
        },
        5: {
            sorter: "shortDate"
        },
        6: {
            sorter: "shortDate"
        }
    },
    textExtraction: {
        3: function (n, t, c) {
            return $(n).attr('data-date');
        },
        4: function (n, t, c) {
            return $(n).attr('data-date');
        },
        5: function (n, t, c) {
            return $(n).attr('data-date');
        }
    },
    widgets: ['zebra', 'columns']
});

new Date('1/1/1930').getTime()
// returns -1262282400000