1. Open calendar Preferences. Select Preferences in the menu at the top of your screen.

2. In Preferences dialog select Accounts tab.

3. In Accounts tab click on "+" button at the bottom to add new account:

4. In Account Type select CalDav:

5. Enter your hiTask user name and password.

6. In Server Address field enter secure.hitask.com/calendar/<username> where <username> is your hiTask account user name. For example if your user name that you use to log in to HiTask is john, calendar address will be secure.hitask.com/calendar/john

The dialog will look like this:

And that's it!

Please note that it may take a minute until tasks appear in your calendar.