I found a new job but have to wait a month to go there and I am still employed at a shitty company, how can I survive?

Long story short, I am employed at a very shitty company, thay treated me poorly. They push harsh targets on us and since I know I won't be staying I can't give a fuck about meeting the targets. Unfortunately I do need money so I can't quit on the spot or put my 2 weeks notice in just yet, I also don't want to be punished by being forced to come back to the office or having daily talks with the higher ups, so I am kinda forced to do the tasks I no longer care to complete. What to do? :C