Deciseconds (100ms) are not a bad unit when dealing with UI because it is about the fastest reaction time. We can't really feel the difference between 50 ms and

Deciseconds (100ms) are not a bad unit when dealing with UI because it is about the fastest reaction time. We can't really feel the difference between 50 ms and 150 ms (both feel instant), but we can definitely feel the difference between 500 ms and 1500 ms. Centiseconds are too precise, seconds are not enough. Also, it is also possible that the computer is not precise enough for centiseconds or less, making extra precision a lie. Deciseconds are just uncommon. But the problem here is that the user didn't expect the "1" to be a unit of time but instead a boolean value. He never wanted a timer in the first place. By the way, not making the unit of time clear is a pet peeve of mine. The unit is never obvious, seconds and milliseconds are the most common, but you don't know which one unless you read the docs, and it can be something else. My preferred way is to specify the unit during the definition (ex: "timeout=1s") with a specific type for durations, second is to have it in the name (ex: "timeoutMs=1000"), documentation comes third (that's the case of git). If not documented in any way, you usually have to resort to trial and error or look deep into the code, as these values tend to be passed around quite a bit before reaching a function that finally makes the unit of time explicit.