Why do the pendulum clock run slow in summer and fast in winter?

Explanation

As we know that time period of pendulum clock `T=2pi sqrt((L)/(g))` at a place g and `2pi` are constant so `T alpha sqrt(T)`
The length of pendulum in summer increases so time period of pendulum is increased So pendulum takes more time to complete one oscillation and clock becomes slow in summer. Vice-versa in winter it becomes fast as time period of pendulum is decreased due to decrease in length of pendulum.