Task Dates are available in the Sign-up Sheets Pro plugin. In the Free version of the plugin, you can set a date on the sheet as a whole. With Task dates you can instead choose to set dates on each task.
Task Dates display on the frontend as a new column in the main task table. The format the date is displayed uses the same one selected in your WordPress general settings in your admin at Settings > General > Date Format.
Using the main Sheet Date field allows for disabling and removing of the sheet once the date has passed. If you choose to set Task Dates instead, the task itself will become disabled once the date has passed.