A "writing session" refers to a dedicated period of time set aside by a writer to work on their writing tasks or projects. It is a focused and intentional effort to engage in the act of writing and make progress in their work. Full definition
Sometimes it's a matter of taking a lower paying, less demanding job that allows you to conserve brain power for early morning or late night writing sessions. (writerunboxed.com)
They are good for quick reference for the teacher during writing sessions. (tes.com)
I use my phone as a timer for my 90 - minute writing sessions. (rachelheldevans.com)