"Used to store 2 rates (day and night) and reduce the kWh cost price" I chose it for this function meter 2 tariffs. Yes, but it contains no internal clock, and therefore it must in any case make an action (like a model with a single tariff ...) to do manually switch from one tariff to another, then with a clock he could calculate the rate HC / HP alone ...
In addition, the menu is really not very intuitive, with long presses on 2 or 3 keys to the manipulations, but hey, it can be learned by reading the doc.
Finally, the display is not very readable, it must be perfectly pure face to read the values, otherwise it is blurred.