Some columns such as the date, dropdown, timeline, etc. columns have settings which allow you to fine-tune the nature of data you wish to paste into monday.com.
Columns with settings have a gear icon next to them.
When you select a column with settings from the Column dropdown list, a sidebar automatically opens to the right side of the screen. There, you can choose any of the settings available to that column.
To open settings for any of the columns, click on the gear icon to the right of the selected column