Introduction

In this blog, I have described, how to create a simple count down of days (business days alone) in a page with minimal use of JavaScript and HTML.
JavaScript, given below, has three parts-
  • The actual timer, which is triggered every 7 milliseconds, so that you can change as per your wish.
  • myTimerFn() is a function, which sets the start and end dates to get the count down of the business days in between.
  • The actual function, which provides the count of business days for the given start and end dates.
Code
  1. <html>
  3. <head>
  4. <script type="text/JavaScript">
  5. //To call a javascript function using timer (part 1)
  6. var myVar = setInterval(myTimerFn, 7000);
  7. // To call the pass the start and end date to function calculating the business days in between (part 2)
  8. function myTimerFn() {
  9. var d = new Date();
  10. var enDate = new Date("09/28/2016");
  11. //alert (d.toISOString() + " | " +enDate.toISOString());
  12. document.getElementById("demo").innerHTML = workingDaysBetweenDates(d.toISOString(),enDate.toISOString());
  13. }
  14. //Function for finding business days between two dates (part 3)
  15. function workingDaysBetweenDates(stDate, enDate)
  16. {
  17. var startDate = new Date(stDate);
  18. var endDate = new Date(enDate);
  19. // Validate input
  20. if (endDate < startDate)
  21. return 0;
  22. // Calculate days between dates
  23. var millisecondsPerDay=8 6400 * 1000;
  24. // Day in milliseconds
  25. startDate.setHours(0);
  26. // Start just after midnight
  27. startDate.setMinutes(0);
  28. startDate.setSeconds(0);
  29. endDate.setHours(23);
  30. // End just before midnight
  31. endDate.setMinutes(59);
  32. endDate.setSeconds(59);
  33. var diff=e ndDate - startDate;
  34. // Milliseconds between datetime objects
  35. var days=M ath.ceil(diff / millisecondsPerDay);
  36. // alert ( "Days Diff:" + days);
  37. // Subtract two weekend days for every week in between
  38. var weeks=M ath.floor(days / 7);
  39. days=d ays - (weeks * 2);
  40. // Handle special cases
  41. var startDay=s tartDate.getDay();
  42. var endDay=e ndDate.getDay();
  43. // Remove weekend not previously removed.
  44. if (startDay - endDay> 1)
  45. days = days - 2;
  46. // Remove start day if span starts on Sunday but ends before Saturday
  47. if (startDay == 0 && endDay != 6)
  48. days = days - 1
  49. // Remove end day if span ends on Saturday but starts after Sunday
  50. if (endDay == 6 && startDay != 0)
  51. days = days - 1 return days;
  52. }
  54. </script>
  55. </head>
  56. <div id="demodiv" style="border:1px solid black;background-color:yellow;height:50px;"><strong><span id="demo"></strong> </span>
  57. day(s) left </div>
  59. </html>
Output
Please let me know, if you have any issues implementing it.