You've been given great advice. There is nothing I can add that hasn't already been said. The lil bit of time you do have should be given to your new flock member.
And varying your routine isn't a bad thing. Birds love the same patterns, but as we know, life changes in an instant and it's easier to get your bird to adapt and go with the flow now, than after years of the same thing.
Make sure your cage is extra roomie, and your new fid has toys to keep their interest while you are out. Remember, birds are flock animals and prefer company, that doesn't mean another bird, it means you. Or things to occupy them while you can't be with them. A larger than minimum cage can not be stressed enough when you are away for long time periods.