I worked on an analytics system where we appended a random 3 digits to the millisecond resolution timestamp for exactly this reason. It turns out, collisions a

I worked on an analytics system where we appended a random 3 digits to the millisecond resolution timestamp for exactly this reason. It turns out, collisions are far, far more common that the math would suggest. Especially back in the aughts when browser had a lot of individual quirks to deal with.