Alternative for current user when scheduled events are used ?

I need to have a single, unique entity stored for each indivudual session/user that is active. I can use %currentUser for sessions that are started by a user and relate an entity atribute to $currentUser/name. However, %currentUser is empty when scheduled event sessions are used. If multiple sessions are started by scheduled event and they run in parallel, how can I make a distinction between the scheduled event sessions ?
1 answers

You could determine them by start time? 

Start the MF with a create DateTime variable using %CurrentDateTime% as value.