This article describes Wake up by RTC Alarm.

Wake up by RTC Alarm is a BIOS feature that allows a computer to power on automatically at a specified time and date, based on the system’s Real-Time Clock (RTC). This feature is beneficial for setting up scheduled tasks, like system updates, backups, or maintenance, without requiring manual startup.

How Wake up by RTC Alarm Works

1. Scheduled Power-On:

   • The RTC (Real-Time Clock) in your computer tracks time even when the system is powered off. By enabling "Wake up by RTC Alarm," you can configure the system to wake or power on at a specified time and date automatically.

2. Supported Power States:

   • This feature typically works from the S4 (Hibernate) or S5 (Shutdown) states, meaning it can wake up the system even when it’s fully powered down, not just in sleep mode.

3. Configuring RTC Wake-Up:

   • You can access this setting by entering the BIOS or UEFI setup on your computer. Look for an option under Power Management or Advanced Settings called Wake up by RTC Alarm, RTC Wake, or RTC Alarm Power On.
   • Once enabled, you can set a specific time (and sometimes date) for the system to automatically start.

4. Use Cases:

   • Scheduled Maintenance: Useful for businesses to perform updates, maintenance, or backups during off-hours.
   • Automation: Allows you to set up a system for specific tasks without needing to be physically present to power it on.

Example: How to Enable Wake up by RTC Alarm

1. Access the BIOS/UEFI: Restart your computer and press the key (e.g., F2, DEL, ESC) to enter the BIOS.
2. Navigate to Power Settings: Look for Power Management or Advanced settings.
3. Enable RTC Wake: Find the Wake up by RTC Alarm option and set it to Enabled.
4. Set Time and Date: Choose the desired wake-up time (and date, if applicable).
5. Save and Exit: Save changes, exit the BIOS, and the system will now power on automatically at the scheduled time.

This feature helps save energy while ensuring the computer is ready to go at the necessary times without manual intervention.