Note: if you’re using Mac OS X Mavericks and later versions (Yosemite, El Capitan, etc.), please review this article: Adding hiTask to Calendar on Mac OS X Mavericks or Later
Open Calendar Preferences. Select Preferences in the menu at the top of your screen.
In the Preferences dialog, select the Accounts tab.
Inside your Accounts tab, click tthe “+” button at the bottom to add a new account:
For Account Type select CalDav:
Enter your hiTask user name and password.
In the Server Address field enter
<username>is your Hitask account user name. For example if your user name for logging into Hitask is
john, your calendar address will be
secure.hitask.com/calendar/johnThe dialog will look like this:
And that’s it!
Please note that it may take a minute before tasks appear in your calendar.