I wouldnt worry too much. It generally works out ok.
I agree with all the others - 7 hours is far too long for a young one. However as they get older it can be extended.
As for routine. Robbie has 3 routines in his week:
Mon / Tues / Fri - he comes to work with me and its a set day - 8am walkies /8.45 -11am quiet time / 11am walkies / 11.30-1pm quiet time / 1pm till 1.30 walkies / 3pm home time
Tues/Thur - he stays at home till 9.30am - mum picks him up for day until 4pm. Then home time.
Sat/Sun - lay in days - walkies rarely before 10am then whatever the day brings us.
Robbie knows exactly what days are what by what clothes i put on and my actions in the morning. Sounds crazy but he just does.
They have to fit into your routine basically and my advice to you - is have a routine for the days you work and then another for those that you dont. If you are in the same routine 7 days a week you'll be doing early morning walks every day!!
Good luck and welcome to the forum xx