You need to set it ahead, not behind. ;) Otherwise you'll be even more late.

I'm sure it doesn't work for everyone, but I've been doing this for years, and it does help me. Yes, of course you always know that it's ahead, but it takes a moment for that fact to register, and that moment can be just long enough to incite action.

(For those who have read Thinking Fast and Slow, I think this is sort of a "hack" of System 1.) Basically I'm leveraging the reactive part of my mind to help me achieve the result that the more strategic part wants.