Is a short time of light during the 12 hour dark period of the cycle, a big issue??

I was just wondering, since my grow room is in my garage and just is made very poorly. during the 12 hour dark period i have to park my car in every night. This takes at the most 5 minutes and in that 5 minutes the grow box lights up like a light shadow over the plants. will this time of light damage the plant in any way??? Or will it just mean it would take a couple of days more until it is ready?? thank you everyone.

the risk is you can turn a female into a hermaphrodite and lose alot of your yield.

Not a good idea. Why Dont you line thebox with some of this...

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