CREATE TABLE table_name_56 (date VARCHAR2, competition VARCHAR2, venue VARCHAR2)

What date has a competition of 2012 afc challenge cup, and dasarath rangasala stadium, kathmandu as the venue?
SELECT date FROM table_name_56 WHERE competition = "2012 afc challenge cup" AND venue = "dasarath rangasala stadium, kathmandu"
SELECT "date" FROM "table_name_56" WHERE "2012 afc challenge cup" = "competition" AND "dasarath rangasala stadium, kathmandu" = "venue"