Calculate start/end dates and next week number for given week number

gistfile1.txt

def week_dates( year, week_no )
 week_start = Date.commercial( year, week_no, 1 )
 week_end = Date.commercial( year, week_no, 7 )
 week_start.strftime( "%d/%m/%y" ) + ' - ' + week_end.strftime( "%d/%m/%y" )
end

def next_week_no(year, week_no)
  week_start = Date.commercial( year, week_no, 1 )
  week_start.advance(:weeks => 1).cweek
end

# example
next_week_no(2008, 52)