What is the maximum time to write the blog given editor.

The standard time for time-outs is 30 minutes when the page is inactive.

 

As a friendly reminder, don't write anything directly to the editor as there are a lot of factors that you may lose your data aside from timeouts. I would recommend you to draft your work in a Word document or even a notepad. Once you finalized your work, then that's the time you will post it using the editor or even much simpler if you upload your document directly and the site editor would gladly take care of the rest for you.