1 out of 7 flowering July 22

I have seven plants growing out a skylight. I left town for 4 days on July 20, so the place was completely dark at night, and when I got back, I found one of the plants is flowering. I masked off the entire area with black garbage bags so the light from the apartment doesn't leak in at night. Now I'm looking at the other six plants and I'm starting to worry because I can't see either male or female characteristics. Is it freakish for a plant to start flowering on July 22 or 23? I thought it would be at least another month before they showed their sex. What do you think?

I grow outside under a canopy (about 3 metres high, trees about 6/7 metres high) made of trees I have spent some years developing,one side is Palms and trees the other is almost open apart from a few conifirs.I live in Spain so even under this canopy I get good sun it comes in from the open side and filters thru from above. I guess this must reduce the light just enough to fool my girls to flower early becouse by mid july all mine are sexed and ready to go.I rotate my plants within the canopy cos some get more sun than others. once they are sexed I position them so that some come on quite early,and I have one now that is frostin nicely some just starting to frost and others that are just showing few pistals. they range in size from 5 to over 7 feet. So unless your growing in pure daylight yes you can get some early flowering, good aint it lol.

polycultiv, I live in southern California and 2 of my plants outside are flowering already since August 1st. I think maybe its because I started giving them flowering nutrient a few days before August or maybe its because they only get a little over 6 hours of direct sunlight. But then again maybe its both. Yea it is kind of freakish for them to flower in the summer.