1. On the Navigation bar, click Batch.
2. Right click on the batch that you want to check.
3. Click on Properties. You should get a pop up that says "Properties".
4. In the Property column, there's a row that says "Last changed on".  This will give you that last time a change was made to this batch and saved.  It will not track changes that aren't saved.  It will also not track saves made without changes.  

The "Last changed on" row will show you the last time a change was saved for your chosen batch