Frankly, it is not irrelevant when you mined. This pool uses a reward calculation method where the value of each share you submit is calculated as a function of time elapsed since the start of the round.

score_share = exp(t/C)

where t is round duration in seconds, and C is a constant, currently 200. This means the value of each share is exponentially growing as time goes, so old share have significantly lower value compared to recent shares. If you stop mining while others don't, your part of total pool score for that round will decrease exponentially. This is public information, each pool publishes the method it uses to calculate rewards.  You can read the original post about this reward calculation method here: https://bitcointalk.org/index.php?topic=1976.msg50002#msg50002.

Unfortunately, many do not read before taking decisions and feel unjust afterwards.

Hope the pointer helps to get started,
   T