f# Ex 8

// Exercise 8 – General (Continued from Exercise 7)
// Question 3
// Days to month end


open System


let isleap (y:int):bool =
    if y % 400 = 0  then true
    else if y % 4 = 0 && y % 100 > 0 then true
    else false


let daysToEndYear (year:int) : int=
    let mutable days = 365*year
    for i in [1..year] do
        if (isleap(i)) = true then days <- days+1
    days


let daysToEndMonth(m:int,year:int):int =
    let mutable days = daysToEndYear (year-1)
    if m = 1 then days <- days + ((367*m + 5)/12)
    else if m > 1 && (isleap(year)) = true then days <- days + ((367*m + 5)/12 - 1)
    else if m > 1 && (isleap(year)) = false then days <- days + ((367*m + 5)/12 - 2)
    days


printfn "%i" (daysToEndMonth(9,1792))

Console.ReadKey() |> ignore



// Question 4
// Era date


open System

let isleap (y:int):bool =
    if y % 400 = 0  then true
    else if y % 4 = 0 && y % 100 > 0 then true
    else false



let daysToEndYear (year:int) : int=
    let mutable days = 365*year
    for i in [1..year] do
        if (isleap(i)) = true then days <- days+1

    days


let daysToEndMonth(m:int,year:int):int =
    let mutable days = daysToEndYear (year-1)
    if m = 1 then days <- days + ((367*m + 5)/12)
    else if m > 1 && (isleap(year)) = true then days <- days + ((367*m + 5)/12 - 1)
    else if m > 1 && (isleap(year)) = false then days <- days + ((367*m + 5)/12 - 2)
    days


let eraDay(d:int,m:int,year:int) : int= daysToEndMonth(m-1, year) + d


printfn "%i" (eraDay(12,3,1999))

Console.ReadKey() |> ignore