How to Change the Time on Your Computer (Windows, Mac & More)

Your computer's clock does more than display the time. It timestamps files, syncs calendar events, authenticates secure connections, and keeps software running in sequence. When it's wrong — even by a few minutes — things break in ways that aren't always obvious. Here's how to fix it across the most common operating systems, and what to know before you do.

Why Your Computer's Clock Might Be Wrong

Before diving into the steps, it helps to understand why the time goes wrong in the first place.

Most computers use two timekeeping systems working together:

• System time — the clock your operating system reads and displays
• RTC (Real-Time Clock) — a small hardware clock on your motherboard, powered by a coin-cell battery, that keeps time even when the machine is off

When these fall out of sync — or when your RTC battery dies — the clock drifts. Timezone misconfigurations, daylight saving time errors, or a disabled time-sync service can also cause problems without any hardware failure at all.

How to Change the Time on Windows

Windows 10 and Windows 11

1. Right-click the clock in the taskbar (bottom-right corner)
2. Select "Adjust date/time"
3. In the Settings panel that opens, you'll see two key toggles:
   • "Set time automatically" — uses Microsoft's time servers via NTP (Network Time Protocol)
   • "Set time zone automatically" — detects your location

If automatic sync is on and your clock is still wrong, try clicking "Sync now" under the Additional settings section. This forces a fresh sync with Microsoft's time servers.

To set the time manually, toggle "Set time automatically" to Off, then click "Change" and enter the correct time.

⚙️ Note: Manual time changes require administrator privileges. If the options are grayed out, you're likely on a managed or work device where IT controls clock settings.

Windows 7 / 8 (Legacy)

Right-click the clock → "Adjust date/time" → "Change date and time" button → enter credentials if prompted. The Internet Time tab lets you configure NTP sync.

How to Change the Time on a Mac

macOS (Current Versions)

1. Click the Apple menu (top-left)
2. Go to System Settings (or System Preferences on older macOS)
3. Select General → Date & Time
4. Toggle "Set time and date automatically" on or off

With automatic sync enabled, your Mac connects to Apple's time servers. If you need manual control, disable that toggle and set the date and time yourself using the on-screen controls.

Timezone is managed separately — look for the Time Zone tab or section in the same panel. If location services are enabled, macOS can detect your timezone automatically.

How to Change the Time on Linux

Linux distributions vary in how they surface time settings through a GUI, but the underlying tools are consistent.

Graphical (GNOME, KDE, etc.)

Most desktop environments include a Date & Time panel in Settings. The options mirror Windows and macOS: automatic sync via NTP, manual override, and timezone selection.

Command Line (All Distros)

# Check current time and sync status timedatectl # Set time manually sudo timedatectl set-time "2025-06-15 14:30:00" # Enable NTP sync sudo timedatectl set-ntp true # Set timezone sudo timedatectl set-timezone America/New_York 

systemd-timesyncd handles NTP sync on most modern distros. Some setups use chrony or ntpd instead — worth checking which is active if sync isn't working.

Automatic Sync vs. Manual: What's the Difference?

For most home and personal use, automatic sync via NTP is the right call — it self-corrects continuously and handles daylight saving transitions without any input from you.

When the Clock Keeps Resetting

If your computer's time reverts to a wildly incorrect date (often years in the past) every time you restart, the CMOS battery on your motherboard is likely dead. This is the small coin-cell battery (usually a CR2032) that powers the RTC when the machine is off.

Replacing it is a simple fix on desktops — the battery sits in a visible slot on the motherboard. On laptops, access varies significantly by model.

🕐 The Variables That Affect Your Situation

Changing the time sounds like one simple task, but the right approach depends on several factors:

• Operating system version — the menu paths above differ between Windows 10, Windows 11, older macOS versions using System Preferences, and newer ones using System Settings
• User permissions — standard accounts on managed devices may not have access to change system time
• Network connectivity — NTP sync requires an active internet connection; air-gapped machines need manual configuration
• Enterprise vs. personal device — domain-joined computers typically get time pushed from a domain controller, not from the internet
• Hardware age — older machines are more likely to have failing CMOS batteries causing persistent drift

A straightforward toggle in Settings works fine for most personal computers. But if the clock keeps going wrong, or if options are locked down, the underlying cause is usually something in that list above — and the fix shifts depending on which one applies to your setup.