Also, if a similar structure is used anywhere else ("every x seconds..." with very short time steps), they should be converted to dt logic as well, otherwise the game is likely to have some imbalanced elements depending on platform performance (shooting faster/slower, moving faster/slower, etc.)
Few things should run at fixed timesteps, if any, and these should always be at a lower frequency than the minimum game framerate to guarantee you don't accumulate delays and errors.