I had removed the March logs and the D drive has 24 GB now.
The log file is quite huge in size for for each day so I don't think it is good idea to keep for 3 months, so I will suggest to keep the log files for only 1 month (30 days).
Do you agree on this arrangement?
Furthermore, I will also suggest you to copy the log files into the external hard drive before the log files being deleted by the auto cleanup, so that you can always refer it back in case you need to.