If you attempt to close the window or tab that is running the timer, you'll get a popup alert asking if you really want to do that.
Ọ bụrụ na ị nwara imechi windo ma ọ bụ taabụ nke na-agbanye oge, ị ga-enweta nchapụta popup na-arịọ ma ọ bụrụ na ịchọrọ n'ezie ime nke ahụ.