What is the best time to buy prepaid electricity?

I'm curious, when is the optimal moment to purchase prepaid electricity? Is there a specific time of day, week, or even month when rates tend to be more favorable? Are there any external factors I should consider, such as seasonal changes or upcoming holidays, that might impact the cost? As a consumer looking to save money on my energy bills, I'm eager to learn more about how timing can play a role in securing the best deals on prepaid electricity.