Personally, I almost always use here::here(), even when I don't have lubridate attached. But, as jenny mentioned, you've described the situation as it is.
To make this a little bit easier to deal with, you can always add a snippet in RStudio, if you're using it.
snippet hh
here::here("${1}")
Then, you can type hh followed by shift + tab, making the here::here() method slightly less cumbersome.
Here's a little gif I made for a blog post— it's for a markdown snippet, but I'm sure you'll be able to extrapolate for R code!