I do the same .. ive even tried lower .. down to 9.5/14.5 thats where i started noticing yeild loss on alot of plants.. some did fine but not enough to validate keeping it that lowI believe it was established that 12/12 is "the standard" for the best balance for onset of flower & reaching proper DLI.
I personally use 11 on/13 off just to save an extra hour on electricity every day.
Most cannabis cultivars will start flower in the 14.5 on/9.5 off window