> it seems not to be noticeable, it just reloads some functions/methods
> each 1000miliseconds, though

It should be fine. But since there is no seconds readout, I think the only reason why you've got it checking once a second is so that it can appear or disappear fairly promptly when window is switched between fullscreen or not?

There is a different way to do this called "binding", which you can use to trigger something when a variable inside of MoI changes. By using binding to control the visibility of the clock, the clock update interval can then be changed to only once a minute (as in the attached version).

- Michael