This value, in minutes, is the configured or actual length of the collection window for the rolling 24-hour bucket for the current day, still accumulating until the day boundary rolls it into history. On this element it is what you divide the accompanying access-hit byte and frame counters by to turn a raw cumulative count into a meaningful average rate for today's still-open 24-hour bucket, and it is also how you spot a truncated bin -- one whose Duration reads less than the table's normal interval because a clear or restart cut it short. For a normal Curr24H bin this should read 1440 (24 hours in minutes); a value of 300 instead would mean the access-hit counters only had 5 hours to accumulate, so a seemingly low total is expected and not a sign of quiet traffic.