Entries for meets to the home team are usually due by Wednesday. So any amount of last minute changes or absence updates that are sent to me after Wednesday at 5pm are pretty much giving the coaching staff something else to do in the 30min of warm-up.
PLEASE record any absences or special exceptions (leaving early, might not make it not sure yet, arriving late, etc…) by Wednesday at 5pm. It doesn't matter how ridiculous the information, "if you share, we will prepare"
Here’s another reason. The swimmers that are at the meet are not all getting to swim relays, because we have to scratch them when people don’t show. If we know in advance we can get more creative with swim-ups and get more athletes participating.