万年历Calendar、js修改日期

待我称王封你为后i 2022-08-19 15:09 192阅读 0赞

//万年历
    Calendar cal = Calendar.getInstance();
    cal.add(Calendar.DATE,-1); //改变日期,改变年份、月份类似
    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
    System.out.println("today is:" + format.format(Calendar.getInstance().getTime()));//格式化现在的时间
    System.out.println("yesterday is:" + format.format(cal.getTime()));//格式化改变后的时间
    System.out.println(cal.get(Calendar.YEAR));//获得年份
    System.out.println(cal.get(Calendar.MONTH));//获得月份
    System.out.println(cal.get(Calendar.DATE));//获得日期
    System.out.println(cal.get(Calendar.HOUR));//获得小时
    System.out.println(cal.get(Calendar.MINUTE));//获得分钟
    SimpleDateFormat format1 = new SimpleDateFormat("dd");               
    System.out.println("today is:" + format1.format(Calendar.getInstance().getTime()));//格式化现在的时间,获得日期
    System.out.println("yesterday is:" + format1.format(cal.getTime()));//格式化改变后的时间,获得日期
    
    //JS
    var date = new Date();
    console.log(dateToStr(date));  //2015-12-21
    date.setFullYear(date.getFullYear()-1);//年份减1年
    date.setMonth(date.getMonth()-1);//月份减1月
    date.setDate(date.getDate()-1);//日期减1天
    date = new Date(date);
    console.log(dateToStr(date));//2014-11-20
    
    function dateToStr(date){  //date转成字符串
        var str='';
        var month=date.getMonth()+1;
        str=date.getFullYear()+'-'+(month<=9?('0'+month):month)+'-'+(date.getDate()<=9?('0'+date.getDate()):date.getDate());
        return str;
    }
    var date = new Date(Date.parse($("#start").val().replace(/-/g, "/")))  //把input标签选择的时间转成date