Microsoft Outlook has a feature that enables you to place Rosh Hashanah and all Jewish Holidays on your calendar with just a few clicks.
Select the “options” menu, click “calendar options” and then “add holidays”. Uncheck all current choices (those choices already have been added to your calendar and this will duplicate it). Then check on “Jewish Religious Holidays”. Then press the next 3 ok buttons and you’re all set.
Note you can also add Israeli holidays and Canadian holidays if you are interested.