|More meetings, shuffling of the crews and...less ejections?|
As for mid-season, the most recent six-day (with at least one game played each day) drought occurred from June 8-13, 2011, between Eric Cooper's ejection of Oakland batting coach Jim Skaalen on June 7 and ending with Larry Vanover's ejection of then-Padres catcher Yorvit Torrealba on June 14.
If you're thinking of a long-haul week of peace, the most recent seven-day (with at least one game played each day) drought occurred from August 27-September 2, 2009, bookended by Todd Tichenor's ejection of then-Twins shortstop Orlando Cabrera (8/26/09) and Jim Wolf's ejection of legendary Braves manager Bobby Cox (9/3/09). Cox would also be ejected the very next night (9/4) by umpire Brian Gorman.
Though at the current rate of 175 ejections per 2340 games played—or one heave-ho every 13.37 games—the 2012 regular season is projected to finish with 182 ejections, 17 shy of the 199 mark reached in 2011 (down from 201 in 2010), 2012 already has surpassed the '09 season's 165 ejections, though 2012 is on pace to become a season with the second-fewest ejections since the AL/NL merger in 2000, a year which owned 225 ejections of its own. On the opposite side of the spectrum, 2003 holds the 21st century record for single season ejections with 289, followed by 2001 with 243 and 2005 with 227.
All above information is available for reference as part of the UEFL Portal's Historical Data spreadsheet.