See you next tuesday, a helpful script for letting you know what day of what week is [x] days from today

seeyounexttuesday.js

/**
* See you next tuesday,
* a helpful script for letting
* you know what day of what week is [x]
* days from today
* @author Jack Armley
* @param daysNo {interger} - Number of days from today to grab
* @param debug {boolean} [false] - Output a more verbose message
**/

var seeYouNextTuesday = function(daysNo,debug){
  
  // Set some vars and that, yeah
  var days = [
    'Sunday',
    'Monday',
    'Tuesday',
    'Wednesday',
    'Thursday',
    'Friday',
    'Saturday'
  ];
  var currDate = new Date();
  var currDay = currDate.getUTCDay();
  var seeYouIn = daysNo;
  var i = 0;
  var j = currDay;
  var weeks = 0;
  var weekPhrases = [
    {message:'next week'},
    {message:'week after next'}
  ];
  var message = '';

  // Increment i by 1 while it is less than
  // [seeYouIn]. Also, loop through the days array
  // from the current day; when the current day is 
  // greater than days.length, reset to zero and start
  // from the beginning of the days array again.
  while( i < seeYouIn ){
    i++;
    if(j < days.length - 1){
      j++;
    }else{
      j = 0;
      weeks++;
    }
  }
  
  // Return a message if the value of
  // daysNo isn't 0
  if(daysNo !== 0){
    // If the debug parameter has been set to true,
    // return a super-long message
    if(debug){
      message += daysNo;
      message += ' day';
      if(daysNo !== 1){
        message += 's';
      }
      message += ' from today (' + days[currDay] + ')';
      message += ' is a ' + days[j];
      message += ', ';
      if(weeks < weekPhrases.length){
        message += weekPhrases[weeks].message; 
      }else{
        message += 'in ' + weeks + ' weeks';
      }
    }
    // Else, return simply:
    // [target day], [weeks]
    else{
      message += days[j];
      message += ', ';
      if(weeks < weekPhrases.length){
        message += weekPhrases[weeks].message; 
      }else{
        message += 'in ' + weeks + ' weeks';
      }
    }
    return message;
  }
  // Else, throw an error
  else{
    throw new Error('Oops! Try a number of days greater than ' + daysNo);
  }
  
};

/**
* Demo
**/
console.log( seeYouNextTuesday(1) );
console.log( seeYouNextTuesday(10) );