Timing is everything, and that includes when to promote your brand.
There are many ways to set up a marketing calendar. Whichever design you use depends on the focus of your brand's activity.
You may set up a calendar based on your brand's advertising or promotional events and channels...
...or you may set up a calendar based on the holidays or other events available throughout the year.
You may even use a standard Gantt chart or ordinary calendar for easier planning.
Whatever content your calendar may have is up to what your brand needs and offers.