If you are cycling to work and would like to include the commute in your training plan, we would advise you to set your availability for that day to the return time of your commute. You can then do the interval part of the training on the way back home for example. Towards work, you could make it an easy endurance ride and just add it to the day as an activity. You can of course also reverse the order, depending on when you feel fitter and also depending on the facilities at the work, end of the ride, unless your colleagues (and you yourself!) don't mind working with a sweaty and smelly cyclist...
We would advise you to set 1 hour of availability. You can either do the interval training on your way to work or on your way home in the afternoon, whichever is more convenient for you. Your 1-hour endurance ride you just load like a normal activity.