Calculate working hours between two days with JavaScript

Calculating working hours between two days with JavaScript is a regular requirement in large companies. In general, managers want to measure clean performance of the employees, excluding weekends and what is outside the business hours (in my case 9 AM to 6 PM). The problem appears when you cannot use C# or Java or any other language of this type and you are limited to JavaScript. JavaScript cannot offer an elegant solution, but is still offering the functionality.

/// <Reference Name="MicrosoftAjax.js" />

function getBusinessHoursDiff(start, end) {
    /// <summary>Calculate business hours between two dates</summary>
    /// <param name="start" type="Date" maybNeNull="false" optional="false">Start date</param>
    /// <param name="end" type="Date" maybNeNull="false" optional="false">End date</param>
    var e = Function.validateParameters(arguments, [{ name: 'start', type: Date, maybNeNull: false, optional: false },
                                                    { name: 'end', type: Date, maybNeNull: false, optional: false }, ], true);

    // Passing incorrect parameters type will result in returning an empty string, you can change the logic as you wish here
    if (e) return '';

    // Define variables and clone the provides date, we do not want to modify them outside as are passed as reference
    var startDate = new Date(startDate.valueOf());
    var endDate = new Date(endDate.valueOf());
    var count = 0;

    for (var i = start.valueOf() ; i < end.valueOf() ; i = (start.setMinutes(start.getMinutes() + 1)).valueOf()) {
        if (start.getDay() != 0 && start.getDay() != 6 && start.getHours() >= 9 && start.getHours() < 18) {

    return count / 60;

Function is simple, even to be honest I did find it after almost two days. Is also not perfect when it comes to performance as is calculating the different till seconds. Still, if you do not want to be so exact, you can calculate till hours level (setMinutes method with set setHours). I am not sure how suitable is this solution for you, but is for sure something you can start from.


Stop SharePoint converting dates to GMT timezone

I often used with SharePoint custom forms and in general I based my development on SharePoint JSOM. Working with it, I am often requested to update date and time fields using JSOM. But there is a small issue with it.

var dt = new Date();

The code above is with working, with an exception. It converts the date to GMT timezone. If my timezone is GMT + 2, recorded date will have 2 hours less then I have specified. The workaround is to convert the date into formatted string.

var dt = new Date();

Date format function is provided by MicrosoftAjax, which is included by default.

Token endpoint URL for SharePoint Online

To connect to SharePoint Online from external application, including Salesforce, you will need the token endpoint URL. This URL has this format:[tenant]/tokens/OAuth/2?resource=[sender ID]/[sharepoint online host name]@[tenant]

Looks simple. You just need to replace tenant, sender ID and sharepoint online host name with real values:

  • Sender ID: 00000003-0000-0ff1-ce00-000000000000
  • Sharepoint online host name: can be found by URL where your site collection is located. For example, if you site collection URL is, host name will be
  • Tenant: is almost the same as host, just “sharepoint” is replaced with “onmicrosoft”. So if my host is, tenant will be

Just replace the values and you will have a valid token endpoint URL to use for connecting your application to SharePoint Online. I will come back in another article with more details about how this is used in authentication and authorization process against SharePoint Online.