How do you determine Peak Hours and non peak Hours in power distribution?

[MrOmnos]

There is only one utility company here in my country which sells electricity to the consumers. But there are several private energy producers. These produces sell their electricity to the state owned company (SOC) and it then sells it to consumers. The buying rate per Unit is defined by the SOC. There are cases where non governmental entities are allowed to sell directly to the consumers but these are mostly micro hydros powering isolated villages.   

So, here the peak hours are defined by the (SOC). It is a time interval in a day where they presume the demand will peak. This interval remains the same until they decide to make changes to it. Changes are made once in six months or even a year or two. They buy electricity at higher rates in this time interval from the producers.

But in reality the peak hours don't start at the same time every day. They do it this way because I assume they don't have the technology.

How do they do it in your country? I mean there are probably several utility company selling and buying. Who determines the rates and how and where does all the power measurement take place?

[NiHaoMike]

Ohmconnect uses dynamic peaks. No idea how it works behind the scenes.