There are a lot of different options when it comes to planning marketing promotions. Some are better than others depending on how big your team is or how complex your campaigns are. Here are 3 of the easiest and most user friendly platforms to use to get started.
Trello
Trello is an easy way to schedule out your promotions and get a quick view into how balanced your marketing pushes are for the month. Here is a sample trello board for a Marketing Calendar.

And here is what that might look like if you use the Calendar Power Up so you can get a bigger picture view of how your marketing is balanced out for the month.

You can also look at the view by week which is great for weekly or daily meetings, it’s also very shareable as I mentioned earlier.
Airtable
Another tool to consider is Airtable. Airtable, like Trello, has a number of different templates that you can choose from. I modified the Content Calendar template in Airtable to quick mock up the promotional schedule below.
The Airtable calendar view is pretty similar to Trello, I find the interface in Trello a bit more intuitive but Airtable is more robust if you want to build out additional functionality within the ‘base’. It’s a good exercise to try them both first before selecting which is the best for you and your team.

Google Sheets
Another easy way to plan out your calendar is with Google Sheets. It can be a bit more clunky but if you don’t know Trello or Airtable and don’t want to use a new tool it’s a quick and dirty way to set something up quickly. It’s just not as scalable imo.
Here’s what a calendar might look like in Sheets (or Excel).

The pitfalls of spreadsheets for planning marketing promotions are many, including not being able to assign promotions to people or easily move things around without messing up formatting. It also becomes a bit unwieldy once everything is populated.
Final Thoughts
There you have it. Three different planning tools to consider as you start to build out your marketing promotions. These three are certainly not the only ones out there, there are a slew of others that you might want to check out too, but if you just want to get going, the first two I mentioned take about 5 minutes to set up. Good luck with whatever you choose!