update DataUtil

[tunogya]

function getWeekNumber() {
var now = new Date();
var startOfYear = new Date(now.getFullYear(), 0, 1);
var firstSunday = new Date(now.getFullYear(), 0, 1 + (7 - startOfYear.getDay()));
var weekNumber = Math.ceil(((now - firstSunday) / 86400000 + 1) / 7);
return weekNumber;
}