I'd say no, while i agree with what blink says that don't tell the full story. I'd suspect that August the 1st isn't 12/12. The natural light change from summer to autumn is gradual getting shorter by a few minutes each day. If you start 12/12 mid july then on aug 1st the actual light cycle is 14/8 then the change may cause some problems either delaying flowering or with hermies.

Personally i'd check what the natural light cycle is on aug 1st for your location and start that light cycle by covering in mid july rather than going straight to 12/12.

e2a but that still may not work as the plants may still need to wait till the natural light gets short enough to fully ripen the fruits

Ideally you want someone who's done this before tho, but that's what i'd do.

Good luck!