For those of you in the math (or science, in general) world dt should be well known as a symbol describing a small fraction of variable t. As a whole, dt is often used to refer to a small fraction of time. However, I wish to propose a new definition of dt.
dt is the smallest amount of time between two events: Event A shall be when the traffic light turns green. Event B shall be when the driver in the car behind you starts honking his car horn to signal to you to get moving.
This definition came in mind after reading a relevant quote by Dave Letterman, well known comedian, about traffic lights in NYC (more info here). Similar traffic behavior (and lack of traffic education) is often exhibited in this part of the world, too. It is not unusual for drivers to keep on moving after the traffic light have turned red (at least 2-3 cars will make it past the intersection). Don’t even think of stopping when the light is orange. Most likely the guy behind you will slam his breaks to avoid hitting you; and then you will have the unique opportunity to hear what a big malakas you are for stopping at orange.
So, yes Dave, traffic lights are indeed a suggestion, and in order to minimize your own stress, maintain sanity and minimize dt make sure you floor the pedal as soon as the light turns green.