No you're not going nuts, I've heard about it too. Actually I read about it on thsseeds website. Cannabis is considered a short day plant, they have a hormone that is degraded in light. So long night periods like 12/12 allows this hormone to build up to high enough levels and it triggers flowering. Supposed to get the plant flowering a bit faster, and yes, it's 36 hrs according to them folks at thsseeds (1 and a half days) but lots of people just do the 12/12 thing and that works fine too.