I think sampledformat wants the 2 next events starting from now, and these events can be any time, not necessarely on consecutive days !?
If ever you can add "2" to a date to the date incremented by 2, this would only be a solution if there is one event every day.
I suggest something like the following:
$query = "select * from shows where date >= current_date limit 0, 2";
JJ Mouris