Converting Days into Human Readable Duration Text

Question

Given an amount of days, say 25, convert it into a duration text such as \"3 Weeks, 4 Days\"

C# and F# solutions would both be great if the F# variation offers any i

Answer 1

This is a recursive solution. Note that a duration only really makes sense measured against a particular point in time on a given calendar because month and year lengths vary. But here is a simple solution assuming fixed lengths:

let divmod n m = n / m, n % m    

let units = [
    ("Centuries", TimeSpan.TicksPerDay * 365L * 100L );
    ("Years", TimeSpan.TicksPerDay * 365L);
    ("Weeks", TimeSpan.TicksPerDay * 7L);
    ("Days", TimeSpan.TicksPerDay)
]

let duration days =
    let rec duration' ticks units acc =
        match units with
        | [] -> acc
        | (u::us) ->
            let (wholeUnits, ticksRemaining) = divmod ticks (snd u)
            duration' ticksRemaining us (((fst u), wholeUnits) :: acc)
    duration' (TimeSpan.FromDays(float days).Ticks) units []