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

### Instruction:
On what date is there a score1 of 2 - 4 with the opponent Chelsea under 18s?

### Inputs:
table_name: table, columns: ['Match', 'Date', 'Competition or tour', 'Ground', 'Opponent', 'Score1']

### Response:
SELECT Date FROM table WHERE Score1 = 2 - 4 AND Opponent = chelsea under 18s