For example-
skeever attack prompts "youve been poisoned".
At that point in time, you are able to use a cure poison potion to rid the poison and prevent disease, correct?
If i do not use a cure poison potion, then after X amount of time, it turns into disease.
What is the time frame we have to cure poison, before turning into disease? Is only during the duration of the poisoning, so we have to use cure poison immediately?

bump

Poison and disease are separate. Poison doesn't turn into disease. If you're poisoned, you use Cure Poison, and if you get a disease, you use Cure Disease.

contracting a disease comes from attacks from specific creatures.
there is no "youve contracted disease" notification, however i do notice that after some time of "youve been poisoned" without using a cure poison, a disease will show up eventually.

There is a you've contracted disease notification. It usually says "you've contracted rockjoint" or whatever the name of the particular disease is.

strange, ive never seen this. does this happen during battle same as "youve been poisoned?"
are we absolutely sure that uncured poison doesnt turn into disease?

Yes, it occurs during battle. On-hit.

We are absolutely sure.

Yes it shows up in battle. And yes poison doesn't turn into a disease. Poison is just a damage per second that last for a certain amount of time depending on the strength and type of poison used.