Output todays date

Is there any easy way to output todays date on a page?
I am still new to Grav. It would be easy to just do it via custom PHP, but as far as I understood, I can’t just insert php into a page? Why is that?

https://twig.symfony.com/doc/2.x/filters/date.html

{{ "now"|date("m/d/Y") }}

Thanks for your answer.
I just have to insert this as page content? I tried it, but it doesn’t show the date, but just shows up as the same source code.

when using within pages make sure you add following configuration to the page header:

twig_first: true
process:
    twig: true