In What's Wrong With Wednesdays? [1] Johana Rothmann gives some great ideas to NOT start/stop project actions on mondays or fridays.
Her major argument is "overtime" that extends into weekends - which of course might become true.
My other ideas about that is of course the "blue monday" or "friday@home" syndrom - aswell as general jour-fixes and team-meetings to be kept on mon/fri days. In abroad projects you will for sure also NOT have people present for 5 days a week (even if there are some special blinded projectmanagers without any idea about "soft"-facts of their staff & their families)...
nice to read that column anyway... expect future comments on Johanna from me...