插图：
mtwtfSSmtwtfSS 123456712345 one week plus 5 days, you can remove whole weeks safely 12345------- you can analyze partial week's days at start date -------12345 or at ( end date - partial days )
伪代码：
@S = start date@E = end date, not inclusive@full_weeks = floor( ( @E-@S ) / 7)@days = (@E-@S) - @full_weeks*7 OR (@E-@S) % 7SELECT @full_weeks*5 -- not saturday+sunday +IF( @days >= 1 AND weekday( S+0 )<=4, 1, 0 ) +IF( @days >= 2 AND weekday( S+1 )<=4, 1, 0 ) +IF( @days >= 3 AND weekday( S+2 )<=4, 1, 0 ) +IF( @days >= 4 AND weekday( S+3 )<=4, 1, 0 ) +IF( @days >= 5 AND weekday( S+4 )<=4, 1, 0 ) +IF( @days >= 6 AND weekday( S+5 )<=4, 1, 0 ) -- days always less than 7 days
