Why has the status date changed while the status remains unchanged at "Editor Assigned"? I submitted an accepted paper after a second revision to a springer journal on 24th Avril and the status stayed at "Revisions Being Processed " for two days. The status changed to "Editor Assigned" on the 27th. However, it remained at "Editor Assigned" for two days, and the date changed on 29th Avril. What does it mean? 

Thank you very much.
Most likely someone touched the submission, but the status didn't advance. My guess would be that an editor was assigned but declined, and they've assigned another editor.

In any case it's not something to worry about, because it's just the journal's interior processes over which you have no control.