The duration between the last take-off time requested by the aircraft operator and the take-off slot allocated by the Network Manager following a regulation communicated by the FMP, in relation to an airport (airport delay) or sector (en-route delay) location.
See also ATFM delay causes and codes.
Please note that software release 20.0 of the Network Manager on 04 April 2016 introduced a change to improve the accuracy of the ATFM delay calculation for operational purposes.
ATFM delays data and graphs in this website take this change into account as of April 2016.
For more information on the the change in methodology click here.