Bosses which do not have 1 enrage timer that remains present and ticking for the entire fight must be manually timed. Dhuum submissions can exclude the pre-event as timing can be done based off of Dhuum's health bar appearing, which is at exactly 2:12. It is worth noting that ArcDPS logs are fairly accurate (~100ms off).
However, the timing method most commonly used in raids is Time = [Total enrage] - [Time left]. This means a kill with x:59 remaining will be a x:01 kill time. This timing method is not extremely accurate compared to manually timing the runs, but it comes close and is very simple.
When the enrage timer appears, it ticks down by 1 second within only a few frames. This means for bosses which have their enrage timers appear about 1 second delayed from actual combat, the timer is fairly accurate. This is the case for most bosses, and only stopped being true for every boss starting in wing 4. Instead of having exceptions for these bosses, the timing method will be kept consistent as it still works for comparison purposes.
##Bosses which start with their enrage timer: Cairn Broken King Deimos Qadim the Peerless
##Bosses which have about a 1 second delay before their enrage timer appears: Vale Guardian Gorseval Sabetha Slothasor Matthias Samarog Keep Construct Xera Mursaat Overseer Samarog Soulless Horror Eyes Dhuum Conjured Amalgamate Largos Twins Qadim Adina Sabir
Below is data gathered from different videos to give an objective view of the timing system.
#Vale Guardian Video referenced (29.97 fps) A condition is applied to the boss at 0:03, frame 18, and he applies a unique buff to himself 1 second later. An enrage timer of 8:00 appears at 0:04, frame 21. The enrage timer ticks to 7:59 at 0:04, frame 24.
The enrage timer ticks to 5:56 at 2:07, frame 22. The boss dies at 2:08, frame 14.
If timing of this run starts upon combat, it would be timed as 2:04.833. If timing of this run starts upon boss UI appearing, it would be timed as 2:03.733.
#Cairn Video referenced (30 fps) "Follow Glenna" disappears from the UI at 0:02, frame 24. The boss' hitbox appears at 0:03, frame 2. The boss' first movement occurs at 0:04, frame 24 while still invulnerable. An enrage timer of 8:00 appears at 0:05, frame 27, the boss becomes vulnerable, and is hit. It's very hard to see when the timer ticks to 7:59 in the video but it seems to happen 3 frames later.
The enrage timer ticks to 7:04 left at 1:00, frame 28. The boss is dead at 1:01, frame 27.
If timing of this run starts upon the boss becoming vulnerable, it would be timed as 0:55.967. However, if the timing of this run starts upon the boss' first movement, it would be timed as 0:57.067.
#Mursaat Overseer Video referenced (30 fps) Claim is interacted with at 0:59, frame 24 and appears on his UI the next frame. The boss aggro arrow appears at his feet at 0:59, frame 27. The very bottom of the level 80 next to his health bar also appears on this frame, which means he has spawned. An enrage timer of 6:00 appears at 1:00, frame 25.
The enrage timer ticks to 5:59 at 1:00, frame 28. The enrage timer ticks to 5:58 at 1:01, frame 25. The enrage timer ticks to 5:57 at 1:02, frame 27. The enrage timer ticks to 5:56 at 1:03, frame 25. The enrage timer ticks to 5:57 at 1:04, frame 27.
The enrage timer ticks to 5:03 left at 1:56, frame 25. The boss and UI disappear at 1:57, frame 16
If timing of this run starts upon the boss spawning/assumed combat, it would be timed as 0:57.600. If timing of this run starts upon boss UI appearing, it would be timed as 0:56.967.
#Samarog Raw footage of warrior PoV (60 fps, but game is ~40 fps) First condition applied at 0:00, frame 0. Enrage timer of 11:00 appears at 0:01, frame 8. The enrage timer ticks to 10:59 at 0:01, frame 14.
The enrage timer ticks to 7:58 at 3:02, frame 13. The boss UI disappears at 3:03, frame 7.
If timing of this run starts upon combat, it would be timed as 3:03.167. If timing of this run starts upon boss UI appearing, it would be timed as 3:02.033.
#Dhuum https://imgur.com/a/imXhFS4
