working out on only the weekends?

So now that i've gone to university, i feel like i practically have no energy/time left for working out on weekdays since i have to wake up at 5am and come back very late. I could technically do a very short 15-30min workout but I'm so tired when I come home

will i still be able to make gains if i only workout on the weekend? which are gonna be friday and sunday for me. on the brighter side, im getting way more steps in due to all the walking I have to do (5-10k steps per day with a heavy backpack)