Formal:
* Quando você gostaria de sair? (When would you like to hang out?)
* Quando podemos nos encontrar? (When can we meet?)
* Que dia você está disponível para sair? (What day are you available to hang out?)
Informal:
* Quando você tá afim de sair? (When are you up for hanging out?)
* Que dia você tá livre pra gente sair? (What day are you free for us to hang out?)
* Que tal sairmos [dia da semana]? (How about hanging out [day of the week]?)
Even more casual:
* Vamos sair um dia desses? (Let's hang out sometime?)
* A gente podia sair, né? (We could hang out, right?)
* Você topa sair [dia da semana]? (Are you up for hanging out [day of the week]?)
Important Considerations:
* Context: The level of formality you use will depend on your relationship with the person.
* Specific plans: If you have a specific activity in mind, you can include that in your question (e.g., "Quando você quer ir ao cinema?" - When do you want to go to the movies?).
No matter which phrase you choose, it's always a good idea to be open to suggestions and flexible with the timing. Enjoy your time hanging out with your friend!