Até qualquer dia!

You use it at the very end of a conversation. It replaces a standard Tchau or Adeus. Simply say it as you are walking away. You can add a smile to make it warmer. It works perfectly when you bump into an old acquaintance. You don't need to schedule a coffee date. Just say the phrase and keep moving.

Use it with people you like but don't see daily. It is great for that neighbor you see once a month. Use it when leaving a party where you met cool people. It works well at the end of a casual business chat. Use it when you want to sound like a local. It shows you are relaxed about the future. It is perfect for ending a phone call with a distant relative.

Do not use it if you have a meeting tomorrow. That would be confusing and a bit weird! Avoid it in very stiff, formal legal settings. It might sound too nonchalant there. Don't use it if you are actually angry with someone. It sounds too friendly for a 'breakup' moment. If you have a specific date set, use Até amanhã instead. Using it with your spouse every morning might make them think you're moving out!

Portuguese culture is generally social and flexible with time. We love leaving things open-ended. This phrase reflects that 'relaxed' vibe perfectly. It avoids the heaviness of a permanent goodbye. In Brazil and Portugal, social circles are often fluid. This phrase acts as a bridge between 'friend' and 'acquaintance'. It suggests that the world is small. We will surely cross paths again soon.

You might hear Até um dia desses! which is very similar. Some people just say Qualquer dia a gente se vê! for more emphasis. In more casual settings, you might hear A gente se vê por aí!. All of these share the same 'low-stakes' energy. They all focus on the certainty of the reunion. The timing is just a minor detail.