I like to journal off-and-on all day long, lately. I have gone far too long neglecting my journals, so nowadays, I'm making up for lost time.
I've thrown myself into self-care, and journaling is a major part of my health regimen. I love it. So I'm open to writing any time of the day, but ideally, I think the morning would be the best time to write.
I prefer pen and paper over digital, because I find satisfaction in the act, the motion, of writing. I also like to be able to do sketches or little paintings on the pages. So I have built up a nice collection of different kinds of journals and pens and markers.
That said, digital is much more convenient, so I use a variety of apps, including Fabulous, to gently prompt me, to keep me on track, and to support my efforts.