i am writing a function in javascript that will return date array of all sundays. below you can see my code :

function getDefaultOffDays(year){
var offdays=new Array();
i=0;
for(month=1;month<12;month++)
{
    tdays=new Date(year, month, 0).getDate();

    for(date=1;date<=tdays;date++)
    {
        smonth=(month<10)?"0"+month:month;
        sdate=(date<10)?"0"+date:date;
        dd=year+"-"+smonth+"-"+sdate;

        day=new Date();
        day.setDate(date);
        day.setMonth(month);
        day.setFullYear(year);

        if(day.getDay() == 0 )
             {              
               offdays[i++]=dd;

             }
    }
}

return offdays;
}

the issue is that the returned array is giving random dates not the only dates for sunday :( m i missing some thing?

i am writing a function in javascript that will return date array of all sundays. below you can see my code :

function getDefaultOffDays(year){
var offdays=new Array();
i=0;
for(month=1;month<12;month++)
{
    tdays=new Date(year, month, 0).getDate();

    for(date=1;date<=tdays;date++)
    {
        smonth=(month<10)?"0"+month:month;
        sdate=(date<10)?"0"+date:date;
        dd=year+"-"+smonth+"-"+sdate;

        day=new Date();
        day.setDate(date);
        day.setMonth(month);
        day.setFullYear(year);

        if(day.getDay() == 0 )
             {              
               offdays[i++]=dd;

             }
    }
}

return offdays;
}

the issue is that the returned array is giving random dates not the only dates for sunday :( m i missing some thing?

• javascript

4 Answers 4

If you examine the result, you can see that it's actually not random. It returns the dates for january that are sundays in february, and so on.

The month property of the Date object is zero based, not one based. If you change this line, the function will return the correct dates:

day.setMonth(month - 1);

Also, the loop only runs from 1 to 11, you need to include december too:

for (month=1; month <= 12; month++)

Another way to do this would be to find the first sunday, then just step forward seven days at a time:

function getDefaultOffDays2(year) {
  var date = new Date(year, 0, 1);
  while (date.getDay() != 0) {
    date.setDate(date.getDate() + 1);
  }
  var days = [];
  while (date.getFullYear() == year) {
    var m = date.getMonth() + 1;
    var d = date.getDate();
    days.push(
      year + '-' +
      (m < 10 ? '0' + m : m) + '-' +
      (d < 10 ? '0' + d : d)
    );
    date.setDate(date.getDate() + 7);
  }
  return days;
}

One bug:

for(month=1;month<12;month++)

That's just 11 months.

If you want for the whole year you need:

for(month=0;month<12;month++)

Because there are 12 months in a year. You can even bine that with Guffa's answer.

Month is zero based as like day, so if month is 0 then it Jan, So changed your code as below,

function getDefaultOffDays(year){ 
var offdays=new Array();
i=0;
for(month=0;month<12;month++) { 
    tdays=new Date(year, month, 0).getDate(); 
    for(date=1;date<=tdays;date++)     {
        smonth=(month<10)?"0"+(month+1):(month+1);
        sdate=(date<10)?"0"+date:date;
        dd=year+"-"+smonth+"-"+sdate;
        var day=new Date(year,month,date);
        if(day.getDay() == 0 )              {
            offdays[i++]=dd;
        }
      }
    }
    return offdays; 
  }

This function has error error code:

tdays=new Date(year, month, 0).getDate(); 

replace to:

tdays=new Date(year, month, 1).getDate(); 

becouse 0(day) return prev month