I did this with my orchids during the winter months when I had them under the ligths, but I made sure they had darkness during the day. I noticed in one primary hybrid a delay in growing it's spike. It seemed to do nothing for a while, then started a second spike and both developed nicely. I observed this in both plants from this cross (Phal. stuartiana x Phal. schilleriana)
They delay in growth came when I started giving them light during the night. They hybrids, most Phalaenopsis, some warm growing Dendrobiums and Paphiopedilums didn't show me having problems.
I kept them until March under the lights during the night, so for about 5 months. Back to daylight wasn't a problem at all. I think your plants will be fine if you want to do this for a longer period. I did it to safe on energy bills (electricity is cheaper here during the night) and to give them warmer night (dark) periods because during the day (their night) I had the normal heating on. Otherwise I should have heated the plant room during the nights to keep them warm enough during their dark period.

Nicole

I think it will not be much of an issue in regards to your plants because you actually have the option to supply your indoor plants with much lighting even during the night. I guess the only concern that you will have is the rise of your electricity bills. But I think you should always stick to the light requirements of your plants, that way, you will be able to give your plants adequate lighting without spending too much on electricity ;)

I actually use two growing rooms and one goes on light while the other is dark. I do this because I circulate C0 2 and this way I don't need to add extra heat as the lights provide enough heat to keep the rooms warm, with the C02 circulatioon I do believe they need their totally dark time so no windows or light leaks between rooms will mess up their flowering period. I have never noticed a problem with cycling them in this way. By the way I am a licensed medical marihuana grower in Quebec. Good luck Nelson