The community pools in 324ent world (such as ones around communities of houses, or ones near places like the carnival) are open from dawn to dusk. However, there is another catch.
Every day, a random 3 digit number is posted on the entrance gate to the pool. There is a 3 digit counter display in the shelter area of the pool, that counts up 30-45 times per hour. When the number on the counter reaches the day's chosen number on the gate (when dusk arrives), the pool closes and everyone has to start leaving.
It is possible for the starting number of the day to be higher than the chosen number if the chosen number is below 500. In that case, when the counter reaches 999, it will go back to 000 after that.