Date comparison

I want to show a section between the 1st day of the month and the end date of an ACF (including on that end date as well).

I’m getting hung up on trying to dynamically indicate that it’s the 1 day of the month when using the ‘between’ condition in the 1st conditional. e.g. https://share.getcloudapp.com/7KuQezQn.

Originally I thought I could just put ‘1’ and then compare it that way, but that would mean I would have to change my dates to just include the day instead of m-d-y which isn’t ideal.

Would using something like stringtotime be better? I see you can dynamically add dates to a string to time option such as this:

echo strtotime("+1 day"), "\n";

But I’m not sure if that is the correct usage.

Thanks.