Responses

time1 will return the time the server started and won't change, ie will always be 27/06/2020 18:16:59
time2 will work as I expected it to work, showing the current time the page was loaded

Saturn Routing

open System
open Saturn.Application
open Saturn.Router
open Giraffe.ResponseWriters

let time () = DateTime.Now.ToString()

let timeHandler next context  =
    text (time ()) next context

let routes = router {
    get "/time1" (text (time()))
    get "/time2" timeHandler
}

let app = application {
    use_router routes
}

[<EntryPoint>]
let main argv =
    run app
    0