java 獲取當天(今日)零點零分零秒
日期格式
Calendar calendar = Calendar.getInstance();
calendar.setTime(new Date());
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
Date zero = calendar.getTime();;
時間戳格式
long current = System.currentTimeMillis();
long zero = current - (current + TimeZone.getDefault().getRawOffset() )% (1000*3600*24)