Wrong time.Duration calculated

Question

I have an HTTP server that returns the "uptime" value. The short version of the code:

package main

import (
    "fmt"
    "net/http"
    "time"
)

var startup time.Time

func main() {
    startup = time.Now()
    http.HandleFunc("/", RootHandler)
    http.ListenAndServe(":39000", nil)
}

func RootHandler(w http.ResponseWriter, r *http.Request) {
    now := time.Now()
    fmt.Fprintf(w, "startup: %s\nnow: %s\nuptime (.Since): %s\nuptime (.Sub): %s",
        startup.Format("2006-01-02 15:04:05"),
        now.Format("2006-01-02 15:04:05"),
        time.Since(startup).Round(time.Second),
        now.Sub(startup).Round(time.Second),
    )
}

I started the server at 22:10:33 and after about 1h10m I put my computer to sleep. In the morning, after the computer awake, I got the next response:

startup: 2021-11-18 22:10:33
now: 2021-11-19 05:35:20
uptime (.Since): 1h13m14s
uptime (.Sub): 1h13m14s

I'm working on windows, but the code was executed from WSL v2. Can someone explain why is time calculated wrong?

PS If I'm running directly from windows - the response is fine (time difference calculated correctly).

Answer 1

Your code seems fine. From my understanding WSL v2 is it's own environment. In which case, it's getting the time from there. I would check the time on the system.

https://tomssl.com/fixing-clock-drift-in-wsl2-using-windows-terminal/