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- So to manage time on Linux,

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there are three tools that matter.

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There is date.

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Date is what allows you to check time

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in time display format.

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You can even set it,

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but setting time with date
is not really convenient.

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I would advise against it.

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There's hwclock,

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which allows you to
manipulate the hardware time

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and synchronize the hardware
time to the system time.

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And there's timedatectl.

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Timedatectl is a relatively new utility

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that allows you to manage
time related properties.

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Let me show you.

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So, let me start by typing date.

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Here we go.

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Date is printing the date.

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Now you can use date
with specific formats.

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So if you want date + %d-% m-%,

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uppercase Y for instance.

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Then you see day, month,
year in four digit format.

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This is, by the way,
convenient because I like using

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something like this in backup commands,

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as in, sudo tar cvf;

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and then we create a file, right?

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And I create the file.

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Let's call it "TMP backup-"

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and then the command substitution.

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Remember if you put it
between a dollar and braces

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and you use the result of a command

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in the actual command you are running.

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And this would mean that we create a file

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with the name backup dash date

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of the date, .tar, of the
etc directory or whatever.

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That's one convenient way of doing it.

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So, ls-l on /tmp/backup, whatever.

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There you can see the
backup file was created.

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And just imagine that you
can use this from a script.

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If you put this simple command

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in a script that you can
schedule it with Chrome,

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which we will talk about shortly.

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And you make sure that every
single day you create a backup

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of your system.

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Isn't that cool?

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Let's have a look at
hwclock, not just hwclock.

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Well, that's showing the hardware clock.

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So sudo hwclock is doing what?

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There we go.

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We need sudo privileges.

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The hardware clock and the system clock,

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as you have seen in the video,

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are not always the same.

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And the thing is if your
hardware clock is off,

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when your system boots, it takes it's time

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from the hardware clock.

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So every now and then you
might have to do a synchronize.

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So, sudo hwclock --help.

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And there we can see
the different options.

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If I am going to use systohhc,

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that is how we synchronize
the hardware clock

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with the system time.

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And that is useful if your
hardware clock is off.

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So for the rest of it don't
use this command too much,

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but go and use timedatectl.

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Timedatectl is this new command.

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And in this new command, we
even have tap completion.

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And what else can you do?

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Well, you can use show

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and there you can see all
the different properties,

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including the time zone that we are in

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and whether or not we are using NTP.

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And the time that it
is actually right now.

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So let's manipulate time zones.

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So sudo time, timedatectl set.

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Well before set let's
do a list time zones.

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There you go.

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I wanna be in Africa, Banjul.

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You know where that is?

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In The Gambia, of course.

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So let's go to Africa, Banjul.

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In order to go there,

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Africa/Banjul, we make
that a set time zone.

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And

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there we go.

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And what is the result?

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Well, the result is
what we are going to see

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with timedatectl show.

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As you can see, I'm an Africa, Banjul

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and in Africa, Banjul it's 22:51.

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I don't like it to be 22:51.

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So let's get back to America, Los Angeles.

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But before doing that, we
do need to check the format.

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So list time zones, and
there we go, America.

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And where is it?

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This is what I wanted
to know: Los_Angeles.

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So, set timezone, America,

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Los Angeles

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and there we go.

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And even date is reflecting.

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Date is reflecting what?

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2:52 PM PST.

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That's a standard format
in the date command.

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I think this is about
what you need to know

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about date and hwclock and timedatectl.

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There are many more things
that you can do with it

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but these are not the most common thing.

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So I wouldn't focus on that too much.

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This is what you need to know

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to make sure that your system
is showing the right time.