Starting in version 3.0, Game Schedules may be uploaded from CSV files. Please see the CSV Format documentation for more information on version 4.0 CSV imports.
From the admin pages, select Games->CSV Schedule Import, which provides the following admin screen:
Select a team ID to upload. This is the Team ID, NOT the slug. If the ID exists, games will be uploaded to any existing schedule. If the ID does not exist, it will be created. (Team IDs must not exceed 32 characters.)
Choose a file to upload. This file should be in (PC) CSV format. (Mac format has not been tested.) A description of this file follows.
Press the Import button. A few messages are presented to track the progress of the upload, which should be fast.
Sample .csv files are located in the plugin’s csv-examples folder. I recommend viewing or editing the .xlsx files in MS Excel. One can open the .csv files in Excel, but the date formats will be messed up. Save any changes in .csv format. Upload the .csv files, not the .xlsx files.