You chose in warm weather in the day
Although more gas is used during the day, in warm weather people use less gas - this is not when demand is highest.
In cold weather during the day, people use more gas in their homes so demand is high.
But if demand is greater than the supply, some customers may not receive the gas they need at the correct pressure, and this could be a problem. It could affect heating and cooking at home, electricity generation and even stop some industries from being able to go on working.
What's the solution? Store gas when demand is low, and use it when demand becomes higher.