Date Groups answer the question, "When will the games be played?" There is no need to create a new date group every year. You can override the old date group with new date group information since you'll never schedule games for dates that are in the past.
Log in and click on Elements
Click on Scheduling Administration
Click on Date Groups
Click on the name of the date group
Override the old dates with the new dates.
Save the changes before you add new dates (if applicable).
Don't forget to save your final changes.
Note: There is no limit to the number of Date Groups you can create, and there is also no limit to the number of dates that can be placed within any single Date Group