Linux provides a variety of commands to check the time. The showtime command displays the current time. The date command prints the current date and time, as shown in Figure 6-1.
Understanding time in Linux
In computing, time is a measure of the amount of elapsed time since some arbitrary starting point. In Unix-like operating systems, including Linux, the standard reference clock is the POSIX clocks timer, which increments its count in seconds from 00:00:00 on January 1, 1970 Coordinated Universal Time (UTC). Many other clocks are available as well.
The gettimeofday() system call returns a struct timespec containing two double precision floating point values indicating the number of seconds and nanoseconds since the epoch. The CLOCK_REALTIME clock is based on UTC and advances at a rate of real time seconds per second. It is suitable for measuring elapsed time or CPU usage. The CLOCK_MONOTONIC clock does not have discontinuities caused by changes to the system’s time base (e.g.
How to check time in Linux
In Linux, there are many ways to check the time. One way is to use the date command. To view the current date and time, type: date. The output will show the current date, time, and day of the week. Another way to check the time is to use the timedatectl command. To view the current date and time, type: timedatectl status. The output will show the current date, time, and day of the week.
The date command
The date command is a terminal command that prints the current date and time. It can be used to display the current date and time in different formats, or to print the date and time in a file. The date command can also be used to set the system clock.
The timedatectl command
The timedatectl command is a powerful tool that can be used to view and change the system time and date. This command can be used to set the time zone, configure the time server, and more. The timedatectl command can be run as a standalone command or as part of a systemd unit file.
The hwclock command
Time is a precious commodity, and in order to keep track of it, we need tools to help us. One of these tools is the hwclock command. This command allows you to set and query the hardware clock on your computer. It can be used to set the time manually or automatically using the Network Time Protocol (NTP).
The gettimeofday() system call
The gettimeofday() system call is used to return the current time in seconds since the Epoch. It can be used to measure elapsed time, or to generate a timestamp. The gettimeofday() system call is implemented in the kernel, and does not require any special privileges.
How to set my computer’s BIOS to the correct time?
Computers keep track of time with a little battery-powered clock chip. The BIOS program, which runs when you start your computer, reads the time from this chip and sets the date and time on your computer. If your computer’s date and time are wrong, it can cause all sorts of problems.
How to check if the NTP service is active?
NTP, or Network Time Protocol, is a service used to synchronize the time on network devices. By default, NTP is active on most routers and switches. However, there may be times when you need to check if the NTP service is active.
How to change the timezone in Linux?
There are two ways to do this – using the command line and using a graphical tool. We will start with the command line method. To change the timezone using the command line, you need to first find out what your current timezone is. You can do this by running the following command:
date
This will show you the current timezone setting.