There is no formal publication schedule for supply, use and input-output national data. Eurostat publishes revised and new data transmissions by Member States as soon as they have passed the quality validation.
However, information on the status of the data is available. First the availability overview table indicates its last update on the first sheet and also by its naming; e.g. a file "Availability_091106" has been uploaded on 06 November 2009.
The same system applies for the data by Member State; e.g. a workbook called "Netherlands_Suiot_091023" contains supply, use and IO tables of the Netherlands and has been loaded on 23 October 2009.