Init a task in a module + avoid circular import?

I guess it should be:

main =
 Browser.element
        { init = \_ -> ( initialModel, initialCmd initialModel)

It is advisable to give functions as little data as possible so. Keep the functions small and with parameters as simple as possible.

So… instead of getTimestamps: Model -> Cmd Msg where you would extract some data from the mode, prefer getTimestamps: Int -> Cmd Msg.