When getting approved for a Working Holiday Visa, how long do you have before you have to go to Japan?

Hello, I tried to find this information online but couldn’t find a clear answer.

I (27f), am wanting to spend a year in Japan from September 2024, but I’m unsure of when to apply for the visa, I was thinking of applying in July 2024 so I have time to get my affairs in order before flying off.

Once the visa is approved, how long do I have before I need to actually go to Japan?

Thanks reddit!

Edit: I’m a British Citizen.

by KawaiiFail