Timer is a couple minutes off

I noticed that my timer clicks off a few minutes early, its one of those walmart ones where you press down the blocks and the timer turns like a clock. So basically I'm getting 11 hours and 56 minutes of darkness. Could this be a problem?

11 hours and 56 minuits isnt a problem. Those plastic tab timers can be problematic though.

Is this a serious question or a piss take?

Nothing to worry about . Just don't tell the plants .