Why is it usually preferable to execute the concrete casting at night ?

According to ACI code305 ( Hot weather concreting )Pouring concrete mix during hot weather is possible as long as you have the proper equipment for protection, like Fogging system to moist and reduce the heat from the air.So is advisable and preferable to pour concrete during night time because the temperature is descending and also to avoid also the immature hardening of the concrete which will cause  shrinkage, cracks, and strength loss of the concrete.and in addition daytime pouring with high temperature will give the concrete supplier a very hard time in controlling the temperature of the concrete itself. 

The Temperatures are lower at night than in the day hence lower effect of heat of hydration on Concrete