zul
<datebox id="db1"/>

testCase

click(db1.$n("btn"));
click(jq(db1.$n("pp")).find("@calendar td:eq(12) a"));
click(db1.$n("btn"));

It works well when click td
click(db1.$n("btn"));
click(jq(db1.$n("pp")).find("@calendar td:eq(12)"));
click(db1.$n("btn"));