omatty,
At this time, we don’t offer a way to select specific start days. However, you have the option to move a training plan so workouts can start on Mondays rather than Sunday. To do this, select the Move Workouts link in the right navigation and then move the training plan to begin on Monday instead of Sunday. I hope that answers your question. ~Toby

Hi all - did anything ever come of this?

I just joined but can't find anywhere to change the calendar month or week view to start from Monday (ie the beginning of my training week). This also means that when viewed my A races for next year (which are on Sundays)  are at the beginning of the week - workable of course, but just not that helpful, and slightly bizarre unless I'm missing something...

Thanks for any tips in advance...