Has anyone ever launched a startup while still having a full time job? How did you manage your time?

I have a 9-5 job and I have this idea and I kinda want to put more time into it. I dont know how to manage time to do both and dont want to sacrifice my full time job for something that wont work.<br><br>I feel like I am running out of time and want to do something before I turn 30 and this is my last chance. I dont want to live in regret that I could have at least tried.<br><br>I know Elon Musk does something similar to this, hes working 100 hour weeks on Tesla and also spacex. What is his schedule like?<br><br>How did you launch a startup while still working a 9-5, what was your schedule like, how did you not burn out? I feel like im in a similar situation where I have an idea and I wanna make it happen but I dont wanna sacrifice my job. What did you do?