Format ban duration instead of unban time in login message.

main.go

@@ -427,7 +427,8 @@ func newUser(s ssh.Session) *User {
 			Log.Println("Rejected " + u.Name + " [" + host + "] (banned)")
 			u.writeln(Devbot, "**You are banned**. If you feel this was a mistake, please reach out to the server admin. Include the following information: [ID "+u.id+"]")
 			if banInfo.UseTime {
-				u.writeln(Devbot, "You will be unbaned on "+banInfo.UnbanTime.Format(time.RFC3339))
+				when := time.Until(banInfo.UnbanTime)
+				u.writeln(Devbot, "You will be unbaned in "+formatDuration(when)+".")
 			}
 			s.Close()
 			return nil

util.go

@@ -487,3 +487,28 @@ func genKey() (ed25519.PrivateKey, ssh.PublicKey, error) {
 	}
 	return priv, sshPubKey, nil
 }
+
+func formatDuration(d time.Duration) string {
+	seconds := int(d.Seconds())
+	minutes := seconds / 60
+	seconds = seconds % 60
+	ret := fmt.Sprintf("%v seconds", seconds)
+	if minutes == 0 {
+		return ret
+	}
+
+	hours := minutes / 60
+	minutes = minutes % 60
+	ret = fmt.Sprintf("%v minutes, and %v", minutes, ret)
+	if hours == 0 {
+		return ret
+	}
+
+	days := hours / 24
+	hours = hours % 24
+	ret = fmt.Sprintf("%v hours, %v", hours, ret)
+	if days == 0 {
+		return ret
+	}
+	return fmt.Sprintf("%v days, %v", days, ret)
+}