Bukkit

Some placeholder for system time or unix time would be greatly appreciated. You know, a single numerical value that can easily be compared.
The existing time-related placeholders ($time, $world_time, $todaydate) are not that helpful for many things, like if you want to make sure certain actions can only be done every X seconds or minutes. Especially useful in creation of global or permission-limited cooldowns.
If it was possible to do something like;

$Script$%if%$unixtime>LastAction+120
$text$It has been over 2 minutes since last use
$Script$%else%
$text$This command was last used less than 2 minutes ago.

You could use player's total play time to calculate how much time has passed since last time he used the command. It gets a bit more complex if you need to check when was the last time any player used the command, but I guess you could come up with something there too. A lot more stuff can be done when using placeholders API.