user: Question: What is the original air date of the episode "Another Happy Day"?
Columns: ['Episode #', 'Original Air Date (UK)', 'Episode Title', 'Director', 'Writer', 'Cast']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['3-01', '30 July 1981', 'Night Games', 'Derek Martinus', 'Nick McCarty', 'Stafford Gordon , Roy Holder']
SQL:

assistant: SELECT "Original Air Date (UK)" FROM "Table" WHERE "Episode Title" = 'Another Happy Day';