Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Episode | Location | Headliner | Comedians | Airdate |
| --- | --- | --- | --- | --- |
| 1x01 | Edinburgh Playhouse | Rhod Gilbert | Kevin Bridges Stewart Francis Mark Watson | 6 June 2009 |
| 1x02 | Manchester Apollo | Jason Manford | John Bishop Mick Ferry Sarah Millican | 13 June 2009 |
| 1x03 | Birmingham Hippodrome | Shappi Khorsandi | Steve Hughes Tom Stade Paul Tonkinson | 20 June 2009 |
| 1x04 | Swansea Grand Theatre | Sean Lock | Alun Cochrane Ava Vidal Steve Williams | 27 June 2009 |
| 1x05 | Belfast Waterfront Hall | Patrick Kielty | Neil Delamere Kerry Godliman Jeff Green | 4 July 2009 |
Question:
What date did the show air when Sean Lock was the headliner?
Answer:
27 June 2009