// Convert to seconds if we have a query in ms.
    if ((end & Const.SECOND_MASK) != 0L) {
      end /= 1000L;
      if (end - (end * 1000) < 1) {
        // handle an edge case where a user may request a ms time between
        // 0 and 1 seconds. Just bump it a second.
        end++;
      }
    }

The condition end - (end * 1000) < 1 is always true in fact. So if we request 1554260399000, we will get 1554267600. The correct result is 1554264000.

Expected end scan time: 1554260400 = 1554260399000/1000 - (1554260399000 / 1000 % 3600) + 3600
Actual end scan time: 1554264000 = (1554260399000/1000 + 1) - ((1554260399000/1000 +1) % 3600) + 3600

1554264000 is one hour behind of 1554260400.

We might scan one more row of data. If we delete data, which may lead to delete more.