// 需要提取这种数据 <td>2012-12-17</td><td>11:02 , 12:25 , 13:22 , 15:06 , 15:12 , 19:22 , 23:47</td>
var rawData = '<table><th align="left" scope="col">日期</th><th align="left" scope="col">签到签退时间</th></tr><tr class="GridViewRowStyle" style="height:20px;">'
    + '<td>2012-12-03</td><td>10:16 , 13:22 , 20:05</td></tr><tr class="GridViewRowStyle" style="height:20px;">'
    + '<td>2012-12-04</td><td>11:16 , 14:22 , 21:05</td></tr><table>';
// 方法一
var regexp = /<td>(\d{4}-\d{2}-\d{2})<\/td><td>(.*?)<\/td>/g;
// 加上g标识才会全局匹配，否则只匹配一个
var matchedArray = regexp.exec(rawData);
while(matchedArray != null) {
 console.dir(matchedArray);
 matchedArray = regexp.exec(rawData);
}
// 方法二
var regexp = /<td>(\d{4}-\d{2}-\d{2})<\/td><td>(.*?)<\/td>/g;
// 加上g标识才会全局匹配
var matchedArray = rawData.match(regexp);
console.dir(matchedArray);
// 方法三
var regexp = /<td>(\d{4}-\d{2}-\d{2})<\/td><td>(.*?)<\/td>/;
// 不加g标识
var matchedArray = rawData.match(regexp);
console.dir(matchedArray);
console.log(matchedArray.index);
while(matchedArray != null) {
 rawData = rawData.substr(matchedArray.index + matchedArray[0].length);
 matchedArray = rawData.match(regexp);
}
console.dir(matchedArray);