I bring it up in the interview only if asked. With my current job, I took the job when I was offered it, then mentioned that I needed time off in 2 months for a holiday that was already planned. They didn't even bat an eyelid, just said, sure, put in the form one the first day you start.

And because I work in a consultancy, when I started at a client site, I told the client that 3 weeks after starting, I was taking time off for a holiday that was pre-booked. Again, they took that in their stride.

And I've hired people who then tell me about pre-booked holidays. I am completely ok with that because you don't stop planning your life just coz you're looking for work.

Because your holiday is 6 weeks away I'd only mention it if you were offered the job, or you're asked at the interview.