In this short guide, I'll show you how to sleep until a specific time or date in Linux. Command
sleep can be used in combination with the
Sleep Until a Specific Time
For example, to sleep until a specific time, such as 5:00 PM, we can use the following command:
sleep $(($(date -d '5:00 PM' '+%s') - $(date '+%s')))
This command calculates the number of seconds until 5:00 PM and then tells the sleep command to sleep for that number of seconds.
To understand the command better we can check the following bash example:
current_time=$(date +%s) target_time=$(date -d '04/01/2023 12:00' +%s) sleep_seconds=$(( $target_time - $current_time )) sleep $sleep_seconds
Sleep Until a Specific Date
To sleep until a specific date and time, such as January 5th, 3:00 PM, you can use a command like this:
sleep $(($(date -d 'Jan 5 3:00 PM' '+%s') - $(date '+%s')))
These commands will sleep until the specified time or date in the local timezone of the system on which the command is run.
Sleep and different timezone
To sleep until a specific time or date in a different timezone, we can use the TZ environment variable in combination with the date command.
TZ='Europe/Paris' sleep $(($(date -d 'Jan 5 3:00 PM' '+%s') - $(date '+%s')))
Script will sleep until 3:00 PM on January 5th in Paris, France.
Sleep based on user input
Finally we can use the user input in order to delay/sleep Linux script. The following example show how we can do it:
#!/bin/bash read -p "How long to delay (60 - 60m)? " answer delay=$(echo "$answer * 60" | bc) sleep $delay