Yes he can. The "days" can be totally different than how we experience it because the Author of the Quran is not human. İts none other than Allah. Time outside our reality is totally different...it can be much slower or faster...besides....nothing is impossible to Allah...
It may be 6000 years also since Quran says one day with Allah is one thousand years that we count. Again it may not be referring to the complete phase of creation but a stage within the creation. Just keep in mind that Quran is not a book of science but it is "a book of signs".
In the scheme of things; the earth, moon and sun would seem like grains of sand to Allah. So why would Allah measure the length of his day by microscopic particles that he created?
I think there is a bigger question that you have not asked, how could evolution happen without Allah?