Being able to use "in the last" "last X days" for segments is great, but I'd also like to have the reverse - as in, "not in the last X days."
For example - in my nonprofit, we sometimes send emails to those who have not given in the past 30 days. I can build a segment that shows me everyone whose custom field "latest gift date" is in the last 30 days, and that will update dynamically. But I can't build a dynamically updating segment for those whose "latest gift date" is not in the last 30 days. My current workaround is to include those whose "latest gift date" is before a single specific date. That means I have to update the specific date for each send using that segment, which means I'm not really getting to use dynamic content. That sort of defeats the purpose of segments, doesn't it?
I'm experimenting with using an automation to tag folks as "recent donors" so that I can build segments by excluding that tag, but it's not ideal or as easy as "not in the last X days" would be.