Journal entries posted by users vs Automatic Journal entry posting in SAP

Hi Experts,

I would like to put across my question by sharing an example with you:

The GR-IR account in my SAP system is set to automatic posting only by using (T-Code FS00). Now say for 15 days in a month i maintain this setting. Then for another 15 days the automatic posting configuration is disabled, now users can manually post entries in this account.

Now i want to identify which entries were automatically posted by the system in the GR-IR account and which entries were manually posted by users when the automatic posting setting was disabled.

Some help around this is highly appreciated

Thank you