1, if RTC run fast, please check if there is any noise around X1 and X2 pin. Do not place any highcurrent or high speed signal below X1 X2 layers, if must to do so, please use a ground plane to devide them. Also you can check if the oscillator 's load capacitor is not the correct value.
2, If RTC run slow, please consider the load capacitor and stray capacitance. Also to check the digital lines to ensure they do not have overshoot voltage. Sometimes overshoot on these pin will cause the protection in the ic for a short period. During this time the counter do not work.