Does Time Dilation impact every single cooldown?

…including from items and passive skills (like Blast Shield)? Or just active skills from masteries?

Thanks!

It does not. CDR has a weird mechanic. Similar to RR, there are 3 types of CDR

  1. X% CDR
  2. -X seconds to all abilities on CD
  3. X% for Y% CDR

X% CDR affects:

  • Active skills (e.g. devastation) and Passive Skills (e.g. blastshield) from your mastery
  • Devotions

-X seconds to all abilities on CDR affects:

  • Active skills in your mastery
  • Devotions
  • Active skills granted by items (e.g. mobility runes)

X% for Y% CDR

  • Is a mystery. At least I don’t quite know how it works as you can get multiple sources of it - e.g. bloodlord’s blade + ‘of the gildam arcanum’ suffix.

Does it effect it’s own cooldown or is it not yet considered on cooldown when it procs?

It does not affect itself

Might help.
http://www.grimdawn.com/forums/showthread.php?p=581135#post581135