Is it bad to give minimal notice when leaving a remote contract role?

This role was doomed from the beginning. The company requested a certain start date to which I left my job early to accommodate. Then the employer pushed the start date and I missed out on 6 days of pay. There has been no training, managers answer questions only half the time I ask, give unreasonable deadlines (I’m only 1 month in as of right now). I got offered a new role at another company but it doesn’t start until the 3rd week of April. Do I hold out on telling my current job as long as possible? I fear that since I’m contract they’ll end it the day I tell them. Do you even need to provide contract roles the courtesy of 2 weeks notice? This current role has made me feel like contractors don’t matter as much as regular full time employees the way you are treated and with the lack of any kind of benefit. I do not plan on working for this company again. So what do you think? When should I tell my current job I’m done?