>>109206329There are effectively 3 different time limits.
>existing visa expiration timeFirstly, you can't start the visa extension or type change proceedings without a job, so if it's about to run out then that is your deadline, after which you are considered to be "illegally staying".
>notification timeIf that's not a problem, then you have 14 days from the day of termination to notify Immigration Services Agency. It's just a form to fill out, but if you miss that, you are considered to be "illegally staying".
>visa revocation timeIf you do submit the form, you have a 90 day grace period, but if you're still unemployed after that, Immigration Services Agency can start the visa revocation procedure. You can apply for extension, but it's not guaranteed, and it can only be done once. From looking around on the internet the longest ones are 6 months if you can convince them to refile your visa to "Designated Activities", but then you need to convince them to refile it to a work visa after you find a job(although apparently that's usually not a problem).
TLDR between 2 weeks and 9 months
