ok so in a plants life when it gets 12/12 lighting it will flower not flower faster it will start flowering when you have it on a 12/12 light cycle yes the sooner you do it your yeild will be smaller an you might be able to find a timer that does that but regular plug in timers work fine u just change the lights to stay on for only 12 hours instead of 18 when u change form veg to bud