var weeks = new Array('日','月','火','水','木','金','土');
var now   = new Date();
var year  = now.getYear();
var year2  = now.getYear()-1;
var month = now.getMonth()+1;
var month2 = now.getMonth();
var day   = now.getDate();
var week  = weeks[now.getDay()];
var hour  = now.getHours();
var min   = now.getMinutes();
var sec   = now.getSeconds();

if(year < 2000){year += 1900;}

year2 = year-1;

if ( day >= 15 ) {
document.write('情報更新日：' + year + '.' + month + '.' + '15' + '');
}else{
  if(month2 == 0){
    document.write('情報更新日：' + year2 + '.' + '12' + '.' + '15' + '');    
  }else{
    document.write('情報更新日：' + year + '.' + month2 + '.' + '15' + '');
  }
}

/*
document.write(year + '年' + month + '月' + day + '日（' + week + '）');
document.write(hour + '時' + min + '分' + sec + '秒');
*/