Hi Petra,
Application system expected event extractor has the standard logic to set the expected event date and time .
Check the expected event extractor logic in TM system(/SCMTMS/EXTR_EE_TO - Freight order , /SCMTMS/EXTR_EE_FU for freight unit ) , you can add custom logic as enhancement option in the standard extractor based on the business requirements.
In EM you can change/update the expected event date/time based on the reported event directly in EM and you have to enable the custom activity to update the subsequent event EE date/time & send the updated date and time to TM/ECC system.
Cheers,
Sukumar