如果不能使用java8，建议使用Calendar类来做，代码如下，add方法第二个参数传递负值即可。

Calendar now = Calendar.getInstance(); now.add(Calendar.DAY_OF_MONTH, -30); String endDate = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(now.getTime()); System.out.println(endDate);

java8版本可以使用下面的方法：

LocalDateTime now = LocalDateTime.now(); now = now.minus(30, ChronoUnit.DAYS); System.out.println(now.toString());

如下，最后格式根据需要转化下即可：

var startDate = new Date( new Date() - 24*60*60*1000 * 30 ); console.log('startDate: ' + startDate); // startDate: Tue Jan 19 2016 15:42:19 GMT+0800 (CST)

startDate = nowDate - 30 * 24 * 60 * 60 * 1000

现在时间减去三十天的毫秒数即可。

Date endDate = new Date(); Date startDate = new Date(endDate.getTime() - 30 * 24 * 60 * 60 * 1000);

public class Test { public static void main(String[] args) { Date endDate = new Date(); Date startDate = getDateBefore(new Date(),30); } private static Date getDateBefore(Date d, int day){ Calendar now =Calendar.getInstance(); now.setTime(d); now.set(Calendar.DATE,now.get(Calendar.DATE)-day); return now.getTime(); } }

import org.apache.commons.lang3.time.DateUtils; Date now = new Date(); Date startDate = DateUtils.addDays(now, -30);