I'm pointing towards the fact that a weekly option on SPX will have 7 days to expiry when it's listed, the next day it will have 6 days, then 5 and so on.
So again, I don't see why your system would work only with exactly 7-day options. After all, the difference in greeks is not that great!
who says that i want to talk abaut it? you started to ask me abaut that so i answer. But it goes to nowhere so it doesnt matter.
Again - if anyone knows a dealer, which offer options for DJIA/ SP500 with free to set up expiration date please let me know. That's all. Nothing more abaut strategies.