In Germany the heater is dialed down during the nighthey chat, is that really true?

In Germany the heater is dialed down during the night

hey chat, is that really true? or is this bullshit my landlord made up to save on fuel?

@[email protected] wouldn't it make sense to do it the opposite way? the sun shining... i mean i specifically do not cover my windshield during colder months so that the sun warms up my car