From email: state date tool (?)

This came by email:

Hi everybody,

I downloaded the last version of ganttproject but i know that i can’t use the state date tool, or i don’t know how can i do?

It’s is possible to tell me if this icon i can find?

I am not sure that I clearly understand the question. What do you mean when you say “state date tool”?

I’d like tu change date for knowing the status of project:
For example: The project star 8th january and i’d like to establish that we are 19 january. Actually I know the satutus of project.

Do you mean that you want to create a milestone?

I look that the name is status name.
I found this definition : progress updates?

When you enter progress as percent complete or actual work to date, Project uses the status date to determine where to place actual work and where to schedule remaining work. You can modify the default settings for how the status date is used for placing actual work and remaining work where you want, particularly when assignments are completed earlier or later than scheduled.

And i’m not sur if with gantt project I can do it.
Could you explain me milestone? When I need to use it?

Thank you

Okay, thanks. Something like this I believe:
It is not supported, sorry.