Going past 1311 seconds in any potion effect causes the timer for the effect to have no numbers and the effects never run out (infinite effect time). It would be great if this did not happen. I'd like the option of giving potions 60 minutes of effects time, but currently, it gives infinite time if I try something past 1311.

Example image showing what the effects timer looks like:

http://i.imgur.com/DxnLwp1.jpg

Example recipe:

  name: God Beer
  ingredients:
  - SUGAR/1
  - SPECKLED_MELON/1
  cookingtime: 5
  color: BRIGHT_RED
  difficulty: 1
  effects:
  - FIRE_RESISTANCE/1312
  - INCREASE_DAMAGE/1312
  - SPEED/1312
  - JUMP/1312
  - REGENERATION/1312
  - DAMAGE_RESISTANCE/1312

If I give an effect though /effect it goes infinite after 1638 seconds. This probably is due to the duration being stored in ticks as a short value. 1639 * 20 = 32780, the highest value a short can have is 32767.

The value turns negative, which probably results in an infinite effect. I dont know why it happens after 1311 seconds for you, but i think it is a minecraft issue.