/*
   New Perspectives on JavaScript
   Tutorial 2
   Tutorial Case

   Author: Krystin Scott
   Date:   9/4/09

   Function List:
   showDate(dateObj)
      Returns the current date in the format mm/dd/yyyy

   showTime(dateObj)
      Returns the current time in the format hh:mm:ss am/pm

   calcDays(currentDate)
      Returns the number of days between the current date and January 1st
      of the next year

*/

function showDate(dateObj) {
thisDate = dateObj.getDate();
thisMonth = dateObj.getMonth()+1;
thisYear = dateObj.getFullYear();
return thisMonth + "/" + thisDate + "/" + thisYear;
}
function showTime(dateObj) {
thisSecond=dateObj.getSeconds();
thisMinute=dateObj.getMinutes();
thisHour=dateObj.getHours();

// change thisHour from 24-hour time to 12-hour time by:
// 1) if thisHour < 12 then set ampm to " am" otherwise set it to " pm"
var ampm = (thisHour < 12) ? " am" : " pm";

// 2) subtract 12 from the thisHour variable
thisHour = (thisHour > 12) ? thisHour - 12 : thisHour;

//3) if thisHour equals 0, change it to 12
thisHour = (thisHour == 0) ? 12 : thisHour;

// add leading zeros to minutes and seconds less than 10
thisMinute = thisMinute < 10 ? "0"+thisMinute : thisMinute;
thisSecond = thisSecond < 10 ? "0"+thisSecond : thisSecond;

return thisHour + ":" + thisMinute + ":" + thisSecond + ampm;
}
function calcDays(currentDate) {
// create a date object for January 1 of the next year
newYear = new Date("January 1, 2007"); // insert a temporary date for January 1
nextYear = currentDate.getFullYear()+1; // the year value of the next year
newYear.setFullYear(nextYear); // change newYear to the next year

// calculate the difference between currentDate and January 1
days = (newYear - currentDate)/(1000*60*60*24); // convert milliseconds to days
return days;
}