By default Runn will only allow actuals to be entered for today or the previous days.
However, if you need to allow actuals to be entered for future dates, such as entering scheduled leave for billing purposes, you can enable "Allow future actuals".
This will allow all users to move their timesheets into the future to add timesheets, as well as allowing the API and CSV uploaders to add actuals for any date in the future.
This setting is accessible to admins with Edit Account Settings and Data set as On under Account -> Settings.