It states what it is in the post you quoted: time = number of two-week periods in which you've posted since your registration
Simply put you can only get 14 activity points every two week period. That's all you need to know.
The activity number is determined in this way:
time = number of two-week periods in which you've posted since your registration
activity = min(time * 14, posts)
Can anybody help to explain what's time?
Time fluctuates a bit every two week but if you want to check then you can use
https://www.bctalkaccountpricer.info/ to check the activity period of any account.
Although, As of now it start from Tuesday and ends on Tuesday exactly after 14 days(Referred as time period)
Tuesday, August 1 2017 17:53:20 - Tuesday, August 15 2017 18:00:00
Tuesday, August 15 2017 18:00:00 - Tuesday, August 29 2017 18:06:40
Tuesday, August 29 2017 18:06:40 - Tuesday, September 12 2017 18:13:20
Tuesday, September 12 2017 18:13:20 - Tuesday, September 26 2017 18:20:00
Tuesday, September 26 2017 18:20:00 - Tuesday, October 10 2017 18:26:40
Tuesday, October 10 2017 18:26:40 - Present
Thanks all of your explanations.