The bug
When a potion effect has a duration equal to or higher than 1639, its duration is displayed as "**:**", see also MC-18836.
This implies that the potion effect lasts forever, but this is not the case. However, because of MC-44936 the client will not notice when the duration becomes lower than 1639.
Important: If this report is considered invalid, the field net.minecraft.potion.PotionEffect.isPotionDurationMax should be set to false by the method net.minecraft.potion.PotionEffect.deincrementDuration() if the value is below 1639.
How to reproduce
Use the following command
/effect give @s speed 1639→ ❌ The duration is displayed as "**:**"
Reopen the world
→ ✔ The actual duration is displayed and is decreasing
Linked issues
is duplicated by
relates to
Attachments
Comments
That doesn’t make it any less misleading; also note that the wiki is not an official source.
Avoma
Can confirm in 20w48a.
Avoma
Can confirm in 20w51a.
Avoma
Can confirm in 21w03a.
Avoma
Can confirm in 21w05b.
Avoma
Can confirm in 21w06a.
Avoma
Can confirm in 21w16a.
confirm in 1.17.1
Avoma
Can confirm in 1.18.1.
Avoma
Can confirm in 1.18.2.
Avoma
Can confirm in 1.19.
[media][media]
Avoma
Can confirm in 1.19.2.
marcono1234
I don't believe this is a bug. I just checked the wiki and here is a caption from the Behavior section:
Note that even with commands, effects cannot be made to last forever. If an effect is set to an excessively large amount of time, such as 182 hours [655200 seconds], it will display as "*:*", but will still continue ticking down and eventually expire.
I believe this is implemented just to show that the timer is very high and may never be reached.