Mac El Capitan install from recovery mode reverts back to recovery mode.

I have a 2009 MacBook Pro. I wanted to erase the hard drive and start over since I had a lot of stuff on the computer and I wanted to pass it on to someone else. I entered recovery mode and then I erased the drive and then I went to install OSX El Capitan and it wouldn’t attempt to install until I set the current date and time using terminal. I did that and it went through the install and when it was near the end it went right back to the recovery mode menu. I read online where it said to change the back to 1/1/2015. I tried that and it won’t let the download even start unless the date and time are current. Every time, I try with the current date it does the same thing, it gets to the end and it goes back to the recover mode menu. No error message is given. Please help.