This might sound a bit “duh” when you come to the conclusion but I did have to search for it and couldn’t find an immediate answer.

I want to zero-pad a month variable to always be 2 digits long, using the Twig template engine

Twig doesn’t actually have a built-in filter for this.

{{month|pad('0+',2)}} doesn’t exist.

However, Twig does have a filter called format that gives you access to the power of sprintf.

You can zero-pad the month variable by creating a format string and passing your month value as a parameter to the format filter, like so:

{{ "%02d"|format(month) }}

Easy.

Because this gives you access to the whole set of sprintf format options you can use it to format you variables to just about anything.

Maybe I’m building a website for geeks who would appreciate selecting a month from a list of hexadecimal zero padded values.. {{ "%02X"|format(month)}}

(hopefully not)