Twig：DateInterval格式分钟，前导零不起作用

Question

Twig seems not recongnize the "%l" format to display minutes with leading zero.

The Twig documentation said "when the filtered data is of type DateInterval, when the format must conform to DateInterval::format".

So, if I read correctly the PHP documentation I must use "%l" to have minutes with leading zero but this format is not recongnized by Twig who output "%l" instead of the value. If I use "%i" instead of "%l" I have the correct value, but without the leading zero.

duration is an DateInterval object (correctly set to 6 minutes for example)

{{ duration|date('%i') }} --> output "6"

{{ duration|date('%l') }} --> output "%l" instead of "06"

I don't understand what is wrong...