The window from announcement, notification and actual mobilisation into functioning battalion groups ready for deployment onto the battlefield would even take months for a functioning motivated army with a competent chain of command. This doesn't change much in my view for the immediate state of play on the battlefield, if anything the Ukrainians may push harder and take more risks to recapture territories and fortify them fir future defensive positions.
putin may have proven himself to be a shrewd political operator domestically and in some cases internationally but he is no Julius Caeser when it comes to military strategy.