Welcome to Bluelight.
I wish I had known about proper spacing, and the effects of MDMA on your 5-HT receptors, on serotonin etc. when I was new to it. You'll see a lot of threads here started by people experiencing frightening cone downs and after effects from rolling consequetive weeks, or nights. The typical recommended wait in between uses is a minimum of 30 days, but some feel 60-90 is better. That said, occasionally breaking the rules happens, and most remain fine- but attempting 2 days in a row is something almost everyone deeply regrets. I'd strongly recommend picking the night you want MDMA the most, and enjoy it one night.
You can extend the experience by redosing, but you want to make sure you redose before you start to come down (usually 1-3 hours after your initial pill.) there's no point to trying to roll for 8+ hours, eventually your brain will be done accepting the MDMA and trying to extend it isn't going to help.