找不到用户输入的截止到下一个生日的天数

Question

下面将获得距离这些人生日的天数，如果生日已经过了，它将给你之前的生日

我仍然想知道天气是否可以计算到下一个生日的天数，这需要经过12月，并从1月开始计算。我似乎做得不对

 //Getting birthday and month form form
 var birthdayMonth = document.getElementById('selMonth').value;
 var birthdayDay = document.getElementById('selDay').value;
//Parsing Birthday and month
birthdayMonth = parseInt(birthdayMonth);
birthdayDay = parseInt(birthdayDay);
    //setting date object
    today = new Date( );          // set today's date
    birthday = new Date( );      // set up the Birthday object
    birthday.setMonth(birthdayMonth);      // set birthday month to December
    birthday.setDate(birthdayDay);         // set birthday date to the 15th
if (today < birthday)
 {  //this gets days until next birthday - 
     diff = Math.abs(birthday.getTime( ) - today.getTime( ));
     diff = Math.floor(diff / (1000 * 60 * 60 * 24));
     alert('There are ' + diff + ' days until your birthday ');
  }
else
{ //This gets days since last birthday - 
    diff = Math.abs(today.getTime( ) - birthday.getTime( ));
    diff = Math.floor(diff / (1000*60*60*24));
    alert('It was ' + diff + ' days since your last birthday');
}

Answer 1

试试这个

var birthdayMonth = document.getElementById('selMonth').value;
var birthdayDay = document.getElementById('selDay').value;
birthdayMonth = parseInt(birthdayMonth);
birthdayDay = parseInt(birthdayDay);
    today = new Date( );          // set today's date
    birthday = new Date( );      // set up the Birthday object
    birthday.setMonth(birthdayMonth-1);      // set birthday month to December
    birthday.setDate(birthdayDay);         // set birthday date to the 15th
if (today < birthday)
 {  
     diff = Math.abs(birthday.getTime( ) - today.getTime( ));
     diff = Math.floor(diff / (1000 * 60 * 60 * 24));
     alert('There are ' + diff + ' days until ' + (birthdayMonth)+ ' ' + birthdayDay);
  }
else
{
    alert("B'day has passed!");
}

这是JS Fiddle

希望这能有所帮助！

Answer 2

在这里我已经完成了我试图完成的任务…这将检查距离上次生日还有多少天。这将检查离下一个生日还有多少天。它还将检查今天是否是用户的生日

感谢大家帮助我得出这个结论。在你的帮助下，我得以完成它！我希望这能帮助任何试图做类似事情的人。

var output = '';
        var birthdayMonth = document.getElementById('selMonth').value;
        var birthdayDay = document.getElementById('selDay').value;
        
        birthdayMonth = parseInt(birthdayMonth);
        birthdayDay = parseInt(birthdayDay);
        
        //Date Objects
            today = new Date( );          // set today's date
            birthday = new Date( );      // Birthday object setup e.g(birthday.getTime());
        
            birthday.setMonth(birthdayMonth);      // set birthday month (userInput)
            birthday.setDate(birthdayDay);         // set birthday date (userInput)
        
        //Check if todays the users Birthday
        if(birthday.valueOf() == today.valueOf()){
            sweetAlert("Happy birthday!");  
        }
        
        //Until Next Birthday
        if (today > birthday)
        {
        // If the birthday is passed it will calculate how long until it comes next, even if it's next year.
            birthday.setYear(today.getFullYear() + 1); // Set Year = current year + 1
            diff = Math.abs(birthday.getTime( ) - today.getTime( ));
            diff = Math.floor(diff / (1000 * 60 * 60 * 24)); 
            //alert('There are ' + diff + ' days until your birthday'/*Add this for actual date -> birthday*/); alerting how many days
            output += 'There are ' + diff + ' days until birthday'/*Add this for actual date -> birthday <- */;
        }
        
        //Days since last birthday! e.g(may 20 till today(oct 29))
            birthday.setYear(today.getFullYear()); // Set year is normal. (no +1)
            PRdiff = Math.abs(today.getTime( ) - birthday.getTime( ));
            PRdiff = Math.floor(PRdiff / (1000*60*60*24));
            //alert('It was ' + PRdiff + ' days since your last birthday');  Alerting how many days
            output += '<br />It was ' + PRdiff + ' since your last birthday';
            
            //Output it to the page
            document.getElementById('birthdayOutput').innerHTML = output;

Answer 3

如果他的生日已经过了，你可能没有设置年份。

让我说今天是10月28日，所有其他的生日日期>28&amp；月>10即可。但它在过去的一个月和过去的日期都不起作用。因此，如果今年的出生日已经过了，你应该在年份上加1，这样它就会在下一个生日（即明年）检查。

today = new Date( );          // set today's date
birthday = new Date( );      // set up the Birthday object
birthday.setMonth(11);      // set birthday month to December
birthday.setDate(22);         // set birthday date to the 15th
if (today.getTime( ) >= birthday.getTime( )) //Add current year+1 if birthday already reached for this year
{
   birthday.setYear(today.getYear()+1);
}
if (today.getTime( ) < birthday.getTime( ))
{  diff = birthday.getTime( ) - today.getTime( );
   diff = Math.floor(diff / (1000 * 60 * 60 * 24));
   document.write('There are ' + diff + ' days until ' + (birthdayMonth+1)+ ' ' + birthdayDay);
}

Answer 4

如果您需要计算截至B'day的日期，而不考虑的年份，以下是答案

var birthdayMonth = document.getElementById('selMonth').value;
var birthdayDay = document.getElementById('selDay').value;
birthdayMonth = parseInt(birthdayMonth);
birthdayDay = parseInt(birthdayDay);
    today = new Date( );          // set today's date
    birthday = new Date( );      // set up the Birthday objectbirthday.setDate(birthdayDay);
    birthday.setMonth(birthdayMonth-1);      // set birthday month to December
    birthday.setDate(birthdayDay);         // set birthday date to the 15th
if (today > birthday)
{
    // If the B'day is less than current day means you are refering to the next B'day
    birthday.setYear(today.getFullYear() + 1); // Set Year = current year + 1
}
diff = Math.abs(birthday.getTime( ) - today.getTime( ));
diff = Math.floor(diff / (1000 * 60 * 60 * 24));
alert('There are ' + diff + ' days until ' + birthday);

这是JS Fiddle