Poor uptime for zsh and Windows

uptime.zsh

zmodload zsh/datetime

function uptime() {
    reboot_time=$(net statistics server | awk '/Statistics since/{print $3, $4, $5}')
    strftime -r -s reboot_secs '%d/%m/%Y %H:%M:%S %p' "$reboot_time"
    (( uptime = $EPOCHSECONDS - $reboot_secs ))
    (( up_days = uptime / 86400 ))
    (( up_hours = (uptime % 86400) / 3600 ))
    (( up_minutes = ((uptime % 86400) % 3600 ) / 60))
    (( up_seconds = ((uptime % 86400) % 3600 ) % 60))
    strftime -s now_time '%H:%M:%S' $EPOCHSECONDS

    printf " $now_time up %d days, %2d:%02d\n" $up_days $up_hours $up_minutes
}