An addition to the "show only" buttons in the planet tab.

Planets invaded/colonized within the last 24 hours would be shown here.

Flags. That's part of why we have them.

Unfortunately, there's no filter for flags, so you'd still have to look through a list of planets. You can also forget to take the flag off, do that a few times and you have an even bigger list to look through.

Suggestions. That's why we have them.

What about a sort for colony age? Would provide desired functionality, but for your whole planet database. This way you can just go through yours, enemy, legion, etc. planets and filter your way through them with colony age (All though that wouldn't work with uncolonized obviously..). The planet's tab is very spaced out so an extra column wouldn't compress it too much. Only issue I see with that is the little extra data load when initially gathering the planet list from the database.

+1.

If there were at least some sense to the order in which planets sort themselves by default, it might also help. Every time I apply a filter or sort, the applicable planets are listed, within each grouping, in whatever weird order suits Dan at the time.