bro, photoperiod is the period of time when i switch my lights on.... i had alot of queries about photoperiod as well, whether it be better during day time or nite time... the answer i got was its not about the time of the day, its about giving ur ls enough lighting... also, about giving corals a break, acclimatize them properly... dont tell me if u go to US u would be sleeping all day and wake up at nite to work
cheers bro!