If there is one thing I like about Windows, it is how easy it is to check the calendar uisng the date/time function in the task bar. One click and you can easily look at a monthly calendar and then scroll through for whatever purposes you needed.
It is not there in Mac OS. So I found this great FREE software called MagiCal that works really well. It can show date, time and a calendar and is free (donation will be welcome !). I configure it to show just DAY and DATE but you can choose whatever you needed. And I love BLUE. Good stuff !