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How to dynamically display time in javascript

青灯夜游

Sep 16, 2021 pm 05:04 PM

javascript

How to display time in JavaScript: 1. Use "new Date()" to define a date object; 2. Use the date object's getFullYear(), getMonth() and other methods to obtain the year, month, day, hour, minute, and second values and output them; 3. Use the setTimeout() method to refresh the time value once a second.

How to dynamically display time in javascript

The operating environment of this tutorial: windows7 system, javascript version 1.8.5, Dell G3 computer.

javascript dynamic display time implementation code:

<html>
    <head>
        <title>网页中动态的显示系统日期时间</title>
        <script language="JavaScript">
            function startTime()   
            {   
                var today=new Date();//定义日期对象   
                var yyyy = today.getFullYear();//通过日期对象的getFullYear()方法返回年    
                var MM = today.getMonth()+1;//通过日期对象的getMonth()方法返回年    
                var dd = today.getDate();//通过日期对象的getDate()方法返回年     
                var hh=today.getHours();//通过日期对象的getHours方法返回小时   
                var mm=today.getMinutes();//通过日期对象的getMinutes方法返回分钟   
                var ss=today.getSeconds();//通过日期对象的getSeconds方法返回秒   
                // 如果分钟或小时的值小于10，则在其值前加0，比如如果时间是下午3点20分9秒的话，则显示15：20：09   
                MM=checkTime(MM);
                dd=checkTime(dd);
                mm=checkTime(mm);   
                ss=checkTime(ss);    
                var day; //用于保存星期（getDay()方法得到星期编号）
                if(today.getDay()==0)   day   =   "星期日 " 
                if(today.getDay()==1)   day   =   "星期一 " 
                if(today.getDay()==2)   day   =   "星期二 " 
                if(today.getDay()==3)   day   =   "星期三 " 
                if(today.getDay()==4)   day   =   "星期四 " 
                if(today.getDay()==5)   day   =   "星期五 " 
                if(today.getDay()==6)   day   =   "星期六 " 
                document.getElementById(&#39;nowDateTimeSpan&#39;).innerHTML=yyyy+"-"+MM +"-"+ dd +" " + hh+":"+mm+":"+ss+"   " + day;   
                setTimeout(&#39;startTime()&#39;,1000);//每一秒中重新加载startTime()方法 
            }   

            function checkTime(i)   
            {   
                if (i<10){
                    i="0" + i;
                }   
                  return i;
            }  
        </script>
    </head>
    <body onload="startTime()" style="background-color: #000000;color: white;">
        当前时间：<font color="#33FFFF"><span id="nowDateTimeSpan"></span></font> 
    </body>
</html>

Rendering:

How to dynamically display time in javascript

Methods of the Date object

The Date object allows you to obtain the time relative to the International Standard Time (Greenwich Mean Time, now called UTC-Universal Coordinated Time) or the time the Flash player is running. Operating system time and date. To use the methods of the Date object, you must first create an instance of the Date object.

Date objects must use Flash 5 or later players.

The methods of the Date object are not static, but they can be applied to the specified individual entities when used.

Method introduction of Date object:

getDate ｜ Get the current date (the day of the month) based on local time

getDay ｜ Based on local time Get the day of the week today is (0-Sunday, 1-Monday…)

getFullYear ｜ Get the current year (four digits) based on local time

getHours ｜ Get the current number of hours based on local time ( 24-hour format, 0-23)

getMilliseconds ｜ Get the current number of milliseconds based on local time

getMinutes ｜ Get the current number of minutes based on local time

getMonth ｜ Get based on local time The current month (note that it starts from 0: 0-Jan, 1-Feb...)

getSeconds ｜ Get the current seconds based on local time

getTime ｜ Get the UTC format from 1970.1.1 0: The number of milliseconds since 00

getTimezoneOffset | Get the offset value of the current time and UTC format (in minutes)

getUTCDate | Get the current date in UTC format (the day of the month)

getUTCDay ｜ Get the day of the week today in UTC format (0-Sunday, 1-Monday…)

getUTCFullYear ｜ Get the current year in UTC format (four digits)

getUTCHours | Get the current number of hours in UTC format (24-hour format, 0-23)

getUTCMilliseconds | Get the current number of milliseconds in UTC format

getUTCMinutes | Get the current number of minutes in UTC format

getUTCMonth ｜ Get the current month in UTC format (note that it starts from 0: 0-Jan, 1-Feb...)

getUTCSeconds ｜ Get the current seconds in UTC format

getYear ｜ Get the current abbreviated year based on local time (current year minus 1900)

setDate ｜ Set the current date (the day of the month)

setFullYear ｜ Set the current year (four digits)

setHours ｜ Set the current number of hours (24-hour format, 0-23)

setMilliseconds ｜ Set the current number of milliseconds

setMinutes ｜ Set the current number of minutes

setMonth ｜ Set the current month (note starting from 0: 0-Jan, 1-Feb...)

setSeconds ｜ Set the current seconds

setTime ｜ Set UTC format from 1970.1.1 0: The number of milliseconds since 00

setUTCDate | Set the current date in UTC format (the day of the month)

setUTCFulYear | Set the current year in UTC format (four digits)

setUTCHours | Set the current number of hours in UTC format (24-hour format, 0-23)

setUTCMilliseconds | Set the current number of milliseconds in UTC format

setUTCMinutes | Set the current number of minutes in UTC format

setUTCMonth ｜ Set the current month in UTC format (note that it starts from 0: 0-Jan, 1-Feb...)

setUTCSeconds ｜ Set the current seconds in UTC format

setYear ｜ Set the current abbreviated year (the current year minus 1900)

toString ｜ Convert the date and time value into a string value in the form of "date/time"

Date.UTC ｜ Return the specified UTC Fixed time value in format date and time

[Recommended learning: javascript advanced tutorial]

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