Is Learning HTML and CSS Necessary for Backend Developers?

If you can spare 1-2 hours a day, I'd say spend some time learning the basics of frontend stuff. A couple of weeks should be more than enough to get a decent grasp.

Honestly, you can pretty much ignore the frontend for now. Just concentrate on building your API and use Postman to test things out. If needed, you can always add a simple frontend later without too much hassle.

You should really focus on understanding HTTP more than HTML. As a backend dev, it's more crucial to handle the server-side effectively. Some basic HTML knowledge can help, but making things visually pleasing is best left to frontend developers.

You don't have to go too deep into HTML and CSS for backend work. Just learn the very basics so you're comfortable testing things or creating simple user interfaces. The focus should primarily be on backend development.

It's really up to you. Learning the basics of HTML and CSS can be done quickly, probably in a few days. But if you’re focusing on backend, don't let frontend get in your way. Just enough knowledge to know how things work is good.