Staking does not go off time it goes off number of blocks. Time equals blocks being passed. Then another factor in getting the POS reward is luck that your coin/weight solves the next POS block to get the rewards. Otherwise you keep trying while building coinage/network weight. At some point in time you will get a stake but there is no set time schedule or number of blocks since luck and network weight/coin age are changing factors.  What is being show is the 'best guess' according to the factors at that point in time. Remember that your coins are competing against all of the other coins to win the POS reward.