Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Which Airing date has a Number of episodes larger than 20, and a Genre of modern drama?

### Inputs:
table_name: table, columns: ['Airing date', 'English title (Chinese title)', 'Number of episodes', 'Theme song (T) Sub-theme song (ST)', 'Genre']

### Response:
SELECT Airing date FROM table WHERE Number of episodes > 20 AND Genre = modern drama