Voltage stabilizator turn on with alarm function DS3231

you know these voltage stabilizators with power switching on/off...
For very low conspumtion, is it possible to turn off stabilizator with MCU ATmega328(I think it is possible) and then for wake up use alarm from RTC modul ?

Its realy creazy suggestion, but i want to know if it is possible?
Thank you

Perfectly possible.

As long as - of course - the ATmega328 and the RTC are being powered by a different regulator that is not switched off, because obviously they can do nothing without power.