Time Message Fields

A Time message is immediately generated and sent when there is a PITCH event for a given clock second. If there is no PITCH event for a given clock second, then no Time message is sent for that second. The Time field is the number of seconds relative to midnight Eastern Time. All subsequent time offset fields for the same unit will use the new Time value as the base until another Time message is received for the same unit. The Time message will also include the Epoch Time field, which is the current time represented as the number of whole seconds since the Epoch (midnight January 1, 1970).

A given trading day may span multiple calendar days. Market data recipients must prepare for a crossing of the midnight ET boundary. At such time, a new Time Reference message will be sent and the Time field in subsequent Time messages will reset to reflect the number of seconds from the most recent midnight ET time.