Tag: linux

set-time-once.sh

#!/usr/bin/env bash

set -euo pipefail

# ============================================================
# One-time Ubuntu date/time setter without NTP
# Uses HTTP Date header through proxychains/proxychains4
# ============================================================

# Optional timezone.
# Change this if needed.
TIMEZONE="Asia/Tehran"

# HTTP URLs only. Avoid HTTPS because wrong system time can break TLS validation.
URLS=(
  "http://www.google.com/generate_204"
  "http://example.com"
  "http://neverssl.com"
  "http://cloudflare.com"
)

# ------------------------------------------------------------
# Check root
# ------------------------------------------------------------
if [[ "$EUID" -ne 0 ]]; then
  echo "Please run as root:"
  echo "sudo $0"
  exit 1
fi

# ------------------------------------------------------------
# Find proxychains command
# ------------------------------------------------------------
if command -v proxychains4 >/dev/null 2>&1; then
  PROXYCHAINS="proxychains4"
elif command -v proxychains >/dev/null 2>&1; then
  PROXYCHAINS="proxychains"
else
  echo "Error: proxychains or proxychains4 not found."
  echo "Install it first, for example:"
  echo "sudo apt install proxychains4"
  exit 1
fi

# ------------------------------------------------------------
# Find curl
# ------------------------------------------------------------
if ! command -v curl >/dev/null 2>&1; then
  echo "Error: curl is not installed."
  echo "Install it first:"
  echo "sudo apt install curl"
  exit 1
fi

echo "Using: $PROXYCHAINS"
echo "Disabling NTP..."
timedatectl set-ntp false || true

echo "Setting timezone to: $TIMEZONE"
timedatectl set-timezone "$TIMEZONE"

# ------------------------------------------------------------
# Fetch Date header
# ------------------------------------------------------------
HTTP_DATE=""

for URL in "${URLS[@]}"; do
  echo "Trying: $URL"

  HTTP_DATE="$(
    "$PROXYCHAINS" -q curl -sI --max-time 20 "$URL" \
      | awk -F': ' 'tolower($1)=="date"{print $2}' \
      | tr -d '\r' \
      | tail -n 1
  )"

  if [[ -n "$HTTP_DATE" ]]; then
    echo "Received internet time: $HTTP_DATE"
    break
  fi
done

if [[ -z "$HTTP_DATE" ]]; then
  echo "Error: could not get Date header from any server."
  echo "Check your proxychains config and internet access."
  exit 1
fi

# ------------------------------------------------------------
# Set system clock
# ------------------------------------------------------------
echo "Setting system clock..."
date -s "$HTTP_DATE"

# ------------------------------------------------------------
# Save system time to hardware clock
# Ubuntu normally expects RTC/hardware clock in UTC.
# ------------------------------------------------------------
echo "Writing system time to hardware clock as UTC..."
hwclock --systohc --utc

echo
echo "Done ✅"
echo
echo "Current system time:"
date

echo
echo "timedatectl status:"
timedatectl

echo
echo "Hardware clock:"
hwclock --show

chmod +x set-time-once.sh
sudo ./set-time-once.sh

For a different timezone

Edit this line:

TIMEZONE="Europe/Berlin"

TIMEZONE="Europe/Berlin"

TIMEZONE="UTC"