Casio FC-200 Financial Consultant

[Albert Chan]

(12-26-2020 11:31 PM)Albert Chan Wrote:  return D-E-E - sign(D-7*E + W - 6)

If end date falls on Saturday, and start date not on Sunday, sign correction mess goes away.

Example, networkdays between 1/1/2021 (Friday) to 4/1/2021 (Thursday)

Remove the correction term by adjusting end-date to Saturday, 4/3/2022 Sat

D = 31 + 28 + 31 + 2 = 92 days
E = floor(D/7) = 13 weeks

networkdays (1/1/2020 to 4/3/2020) = D-E-E = 66
networkdays (1/1/2020 to 4/1/2020) = 66 - 1 = 65

PHP Code:

function networkdays(A, B)      -- assumed date A <= B
    local M = 5 - (B-1)%7       -- days to Saturday
    local D = B+M - A           -- B -> Sat
    local E = floor(D/7)
    if D-7*E==6 then D=D-1 end  -- A Sun -> Mon
    if M > 1 then D=D-M+1 end
    return D-E-E
end