String functions

dayStr = document.lastModified;
i = dayStr.indexOf(':');
n = dayStr.length;
document.write("dayStr = " + dayStr + "   i = " + i + "   n = " + n + "<br>");
document.write(dayStr.substring(i+1, n));

convert to Local Time

lastDate = new Date(document.lastModified);
lastDate.setYear(lastDate.getYear()+2000);
lastDate.setTime(lastDate.getTime()-lastDate.getTimezoneOffset()*60000);
document.write("最近更新日期: "+lastDate)