This clock is generally of lousy qualitiy and quits its work pretty soon and easily. Maybe due to humidity reasons also. Who knows.
I had mine replaced under warranty after 2 month. And while the clock works so far til now, the date function again shows weird numbers.
But I don´t give it too much attention. It´s just a tiny little clock/date display.
The clock itself does not have a seperate battery. It is powered by the scoots battery only.
And replacement is pretty much time-consuming, because you have to "rip apart" almost everything around the handlebar and the odometer/speedometer itself to get to the clock for a replacement.
So maybe to be done best when you have to change your brake fluid anyway (recommended approx. every two years).