I am on 
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production.

When I submit

```
Timing start

```

command, I get

```
Timing command is obsolete.

```

I searched a lot but did not find a reason why this is happening. Any thoughts?

Thanks

**EDIT:**  

Tested in Oracle SQL Developer 17.2.0.188

I understand it is an issue of Oracle SQL Developer.  

Thanks for answers.