With this addon you can create cooldowns with good performance, without worrying of deleting variables, etc. Expired cooldowns will be automatically deleted in a very optimized way. Everything is made with maximum performance in mind, you should be able to safely have millions of cooldowns running simultaneously.

Syntaxes

Start a cooldown

(create|start) [a] cooldown %string% for %timespan%

Example: start cooldown "example%player%" for 45 seconds

Stop a cooldown

(reset|stop|delete|clear) cooldown %string%"

Example: stop cooldown "example%player%"

Check if cooldown is over

cooldown %string% (is|has) (finished|over|done)
cooldown %string% is(n't| not) unfinished)
cooldown %string% is(n't| not) (finished|over|done)
cooldown %string% is unfinished

Example:
cooldown "example%player%" is over

Display cooldown time

set {_cd} to cooldown "example%player%"
send "This cooldown will be over in %{_cd}%"

Extend/Reduce existing cooldown

add 5 seconds to cooldown "example%player%"
remove 5 seconds from cooldown "example%player%"

Compatibility

Should work on about any Minecraft version on which Skript works, cooldowns do not interact with Minecraft code in any way
Incompatible with WolvSK addon cooldowns due to syntax conflict, just use Skooldown instead