To answer your question, no its not as important. Roots grow more during dark cycles, so a lot of growers use an 18/6 light schedule to promote more root growth. In my grows I used a 20/4 once and 24/0 once, and noticed only a little more root growth with 20/4, but noticeably faster growth above ground with 24/0. Some say you should have the dark period in veg, others say it really doesn't matter. In the end, I think each grower finds what works best for them through their own experiences :thumbsup:

p.s. Now would be a good time to fix those light leaks