// JavaScript for: http://www.osterberg-class.com/
// Bruce Osterberg, Feb 22, 2008
//
/*Copyright 1996 - Tomer and Yehuda Shiran
      Feel free to "steal" this code provided that you leave this notice as is.
      Additional examples from the book can be found at http://www.geocities.com/SiliconValley/9000/
      For more information contact Tomer or Yehuda Shiran <yshiran@iil.intel.com>*/

setCal()

// initialize time-related variables with current time settings
function getTime() {
      var now = new Date()
      var hour = now.getHours()
      var minute = now.getMinutes()
      now = null
      var ampm = "" 

// validate hour values and set value of ampm
     if (hour >= 12) {hour -= 12; ampm = "PM"
     } else {ampm = "AM"; hour = (hour == 0) ? 12 : hour}
     // (fancy script) hour = (hour == 0) ? 12 : hour
// add zero digit to a one digit minute
     if (minute < 10) {minute = "0" + minute} // do not parse this number!
// return time string
     return hour + ":" + minute + " " + ampm
     }

// Leap year divisible by 4 (except 2000)
function leapYear(year) {
     if (year % 4 == 0) // basic rule
     return true // is leap year
     /* else */ // else not needed when statement is "return"
     return false // is not leap year
     }

// Get number of days in the specified month (parameter)
function getDays(month, year) {
// create array to hold number of days in each month
     var ar = new Array(12)
     ar[0] = 31 // January
     ar[1] = (leapYear(year)) ? 29 : 28 // February
     ar[2] = 31 // March
     ar[3] = 30 // April
     ar[4] = 31 // May
     ar[5] = 30 // June
     ar[6] = 31 // July
     ar[7] = 31 // August
     ar[8] = 30 // September
     ar[9] = 31 // October
     ar[10] = 30 // November
     ar[11] = 31 // December
     return ar[month]
     }

// Get the name of specified month (parameter)
function getMonthName(month) {
// create array to hold name of each month
     var ar = new Array(12)
     ar[0] = "January"
     ar[1] = "February"
     ar[2] = "March"
     ar[3] = "April"
     ar[4] = "May"
     ar[5] = "June"
     ar[6] = "July"
     ar[7] = "August"
     ar[8] = "September"
     ar[9] = "October"
     ar[10] = "November"
     ar[11] = "December"
     return ar[month]
     }

// Setup Calendar's variables
function setCal() {
// standard time attributes
     var now = new Date()
     var year = now.getYear()
     if (year < 1000) {year+=1900}
     var month = now.getMonth()
     var monthName = getMonthName(month)
     var date = now.getDate()
     now = null

// create instance of first day of month, and extract the day on which it occurs
     var firstDayInstance = new Date(year, month, 1)
     var firstDay = firstDayInstance.getDay()
     firstDayInstance = null

// number of days in current month
     var days = getDays(month, year)

// call function to draw calendar
     drawCal(firstDay + 1, days, date, monthName, year)
     }

function drawCal(firstDay, lastDate, date, monthName, year) {
// constant table settings
     var headerHeight = 50            // height of the table's header cell
     var border = 10                  // 3D height of table's border
     var cellpadng = 3                // text from edge of cell
     var cellspacing = 4              // width of table's border
     var headerColor = "black"        // color of table's header, Year!
     var headerSize = "+3"            // size of tables header font
     var colWidth = 65                // width of columns in table
     var dayCellHeight = 25           // height of cells containing days of the week
     var dayColor = "black"           // color of font representing weekday Names
     var cellHeight = 40              // height of cells representing dates in the calendar
     var todayColor = "red"           // color specifying today's date in the calendar
     var timeColor = "purple"         // color of font representing current time
     var brdrColor = "#696969"        // color of calendar border
     var backColor = "#dcdcdc"        // color of calendar background
// #links1 {border: 16px ridge #c0c0c0; background-color:#dcdcdc; font-size: 14px}
// create basic table structure
     var text = ""              // initialize accumulative variable to empty string
     text += '<CENTER>'
     text += '<TABLE BORDER=' + border + ' CELLSPACING=' + cellspacing + ' CELLPADDING=' + cellpadng 
     text += ' BORDERCOLOR=' + brdrColor + ' BGCOLOR=' + backColor + '>'         // table settings
     text += '<TH COLSPAN=7 HEIGHT=' + headerHeight + '>'                        // create table header cell
     text += '<FONT COLOR="' + headerColor + '" SIZE=' + headerSize + '>'        // set font for table header
     text += monthName + ' ' + year 
     text += '</FONT>' // close table header's font settings
     text += '</TH>' // close header cell

// variables to hold constant settings
     var openCol = '<TD WIDTH=' + colWidth + ' HEIGHT=' + dayCellHeight + '>'
     openCol += '<FONT COLOR="' + dayColor + '">'
     var closeCol = '</FONT></TD>'

// create array of abbreviated day names
     var weekDay = new Array(7)
     weekDay[0] = "Sun"
     weekDay[1] = "Mon"
     weekDay[2] = "Tues"
     weekDay[3] = "Wed"
     weekDay[4] = "Thu"
     weekDay[5] = "Fri"
     weekDay[6] = "Sat"

// create first row of table to set column width and specify week day
     text += '<TR ALIGN="center" VALIGN="center">'
     for (var dayNum = 0; dayNum < 7; ++dayNum) {
         text += openCol + weekDay[dayNum] + closeCol 
         }
     text += '</TR>'

// declaration and initialization of two variables to help with tables
     var digit = 1
     var curCell = 1

     for (var row = 1; row <= Math.ceil((lastDate + firstDay - 1) / 7); ++row) {
         text += '<TR ALIGN="right" VALIGN="top">'
         for (var col = 1; col <= 7; ++col) {
             if (digit > lastDate){break}
             if (curCell < firstDay) {text += '<TD></TD>';
                curCell++
             } else {
             if (digit == date) {             // current cell represent today's date
                text += '<TD HEIGHT=' + cellHeight + '>'
                text += '<FONT COLOR="' + todayColor + '">'
                text += digit
                text += '</FONT><BR>'
                text += '<FONT COLOR="' + timeColor + '" SIZE=2>'
                text += '<CENTER>' + getTime() + '</CENTER>'
                text += '</FONT>'
                text += '</TD>'
                } else
                text += '<TD HEIGHT=' + cellHeight + '>' + digit + '</TD>'
                digit++
                }
             }
         text += '</TR>'
         }

// close all basic table tags
     text += '</TABLE>'
     text += '</CENTER>'

// print accumulative HTML string
document.write(text) 
}