Bard Charm Solon's Song of the Sirens - 3 or 4 ticks?
 

I didn't find the answer anywhere so I'll post here. The wiki shows this song has a duration of 4 ticks but I'm seeing 3 elsewhere when I search. I did some testing and can't really tell due to the way the server/client tick works. Can anyone help? 3 or 4 ticks? Thanks! :)

Cast it and time its duration:

If it lasts between 12 and 18 seconds every time then it is 3 server ticks. If it lasts between 18 and 24 seconds it is 4 server ticks.

Notice that the lower level charm according to the Wiki isn't listed as 3 or 4 ticks. It is just given as 18 seconds. This is probably wrong, but easy enough to check.

My understanding (based on some light testing) is that different entities can tick at different times, but for any given entity it seems stable, at least over a time frame of a few minutes, in having six seconds between each tick. E.g. entity "a" ticks at 1:00, 1:06, 1:12, 1:18, 1:24... and entity "b" ticks at 1:02, 1:08, 1:14, 1:20...

If you have a tick based spell that gives a worn off message you can use the time stamp of that message to learn when the entity will tick, and use that to calculate when a tick based spell should wear off. E.g. if you cast a 3 tick spell on "b" and it lands at 1:01, you get a free second till it hits a tick at 1:02, then you get the three ticks of duration and it wears off at 1:20. On "a" landing the same spell at the same time nets you 5 free seconds and it wears off at 1:24.

I think 3 tick spells last 18-24 and 4 tick spells 24-30. I measured mesmerize and mesmerization to last within the 24-30 second range, and I am guessing that those spells' wiki duration of 4 ticks is likely correct.