PRISTINA, Kosovo — Physicists tell us that time expands and contracts because of relativity. Poets and philosophers tell us that time alters with love and age. And, across Europe, microwave ovens tell us that time changes with tussles between Balkan nations.

A dispute between Serbia and Kosovo has disrupted the electric power grid for most of the Continent, making certain kinds of clocks — many of those on ovens, in heating systems and on radios — run up to six minutes slow.

It is one of the stranger examples of technology binding together far-flung parts of the world, and one quirky effect of more than two decades of conflict in the former Yugoslavia.

The slowdown began in mid-January, and since then clocks in 25 countries, from Poland to Portugal and Denmark to Turkey, have lost time. The fluctuation in the power supply is infinitesimally small — not nearly enough to make a meaningful difference for most powered devices — and if it were a brief disturbance, the effect on clocks might be too little to worry about.