js获取当前时间和上一周的开始时间

/**
 * 计算当前时间
 * @returns {String} 返回当前时间
 */
function CurrentTime(){
	var myDate = new Date();
	var year = myDate.getFullYear();
	var month = myDate.getMonth() + 1;
	var dates = myDate.getDate();
	var currentDate = year + "-" + month + "-" + dates;
	return currentDate;
}
/**
 * 计算上周的时间
 * @returns
 */
function getYestoday(){       
    var d=new Date();
    var yesterday_milliseconds=d.getTime()-7000*60*60*24;        
    var yesterday = new Date();        
    yesterday.setTime(yesterday_milliseconds);        
        
    var strYear = yesterday.getFullYear();     
    var strDay = yesterday.getDate();     
    var strMonth = yesterday.getMonth()+1;   
      if(strDay<10)     
   {     
       strDay="0"+strDay;     
    }    
   if(strMonth<10)     
   {     
       strMonth="0"+strMonth;     
    }     
    datastr = strYear+"-"+strMonth+"-"+strDay;   
    return datastr;   
  }