Not sure but maybe if you missed some tasks, then selecting would allow the task items to spawn in the oasis? Like selecting “Check for survivors” will spawn the survivors around the oasis. Not sure because I haven’t missed any days yet but I would imagine having several tasks pile up and automatically spawn in the oasis without selecting them could look hectic closer to the end of the two week period.
You can only "miss" tasks if you try to do them after the event has ended. Tasks are only unlocked each day, you can complete multiple tasks on one day if you have them unlocked.