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We've seen how we can use variables
with PHP to make updates faster.

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Now let's get PHP to make
some actual updates for us.

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PHP has many built in functions that can
be used to handle complex programming

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tasks.

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How long after the New Year do you keep
writing the previous year for dates?

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I'm usually good in January but
then start slipping again in February.

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And who wants to spend their first week
of the New Year updating copyright dates

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in every footer on every web page?

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Instead, let PHP do it for you.

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We'll be using the date function that
we used in the daily exercise program.

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I've included a link to the documentation
in the teacher's notes.

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You've already added code
blocks to this page, so

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you have all the tools that you need.

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Pause this video and
see if you can change the year

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in the footer to have PHP
automatically update that for us.

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Go ahead I'll wait right here.

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So, did you figure it out?

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Don't worry if you didn't
quite get there this time,

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I'll take you through each step right now.

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Down here in the footer,

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we want to replace the year 2016
with the PHP date function.

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To start, we replace the year
with the PHP code block.

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The next step is to add our function call.

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This time we want the date function
to return the four digit year, so

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we pass the capital Y in
quotes to the date function.

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Check the teacher's notes for a link to
the docs with all the options available.

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For controlling how the date
function outputs date information.

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Let's save the file and
refresh the browser.

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Now the year is gone completely but
there's no errors, so what went wrong.

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Let's go back to work spaces.

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The call to the function is good but
it only returns the value,

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we haven't told the script what
we want to do with the value.

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For our daily exercise program we assign
the value to a variable called Today.

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This time we just want
to display the value,

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so let's add the echo
command before the date.

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Now we can save and
refresh our browser again.

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Great, this time we see the current year.

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Awesome, now we don't have to worry about
updating that date for the new year.

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But PHP provides even more built
in functions that we can use,

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sometimes the page may also
contain our last modified date.

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This can be helpful for

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information that is time sensitive
such as news or a report.

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But I don't wanna have to rely on my
memory to update that last modified date,

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we could be in trouble if we did.

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PHP to the rescue, let's pull up
the docs for the date function.

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In the docs for

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the date function, we can see that we can
pass a second optional parameter as well.

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By default it uses the current
timestamp this moment in time.

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But we can also specify a timestamp if
we want to use a different date or time.

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There are many different ways to
use PHP to create a timestamp,

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let's scroll down to the see also heading.

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For this solution, I want to get
the timestamp of the last modified date

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to do that we use
a function call getlastmod.

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Getlastmod, gets the time of the last
modification of the current page.

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Since a function returns a value,

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I can use a function within another
function to supply a value.

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If you scroll down you can see the first
example on the getlastmod page.

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Let's copy this code block and
use it in our footer as well.

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We can also combine these code blocks,
so that it's all one code block.

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Combining code blocks when there's no HTML
separating them can once again make things

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easier to read.

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Now let's save this page and
refresh our browser.

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So, now we see last modified with a month,
day, year and time.

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When we refresh the page,

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the last modified date doesn't change
because we have not resaved the file.

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We should put some space separating
the name and the last word.

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So let's modify the file again and
add a period and a space.

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Let's add some things here.

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We wanna space after the year and

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we'll add a period and a space at the end.

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This time when we refresh the browser,
we see a period and a space.

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We also see that the time did change
because we made changes to the file.

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Nice work, you're learning to make use of
one of the programmers' greatest strengths,

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laziness.

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According to Larry Wall author of
the Perl Programming Language,

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laziness is one of the greatest
virtues of a programmer.

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Because it makes you go through great
efforts to reduce how much energy you use.

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Laziness makes you write labor saving
programs that other people find useful.

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And if you're lazy, you won't wanna answer
a lot of questions about your program.

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So, make sure that you
document your code well.

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Lazy or not, reducing the amount
of busy work I need to do.

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Gives me more time to do the ever
increasing list of things that

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I want to accomplish.

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Besides, it sure is rewarding to build
something that's actually useful.

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Let's finish off this course by
combining the unit converter and

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the daily exercise programs
into this page as well.