DailyEdge.ie rounds up the TV shows that you’ll be tweeting about tonight and talking about tomorrow.

I Am Irish (RTÉ2, 9.30pm)

The last in a series of three documentaries on modern Ireland – previously, we had I Am Immigrant and I Am Traveller. Journalist Una Mullally interviews various people about what it means to be Irish. #IAmIrish

How To Stay Young (BBC1, 9pm)

In this new series, Angela Rippon and Dr Chris van Tulleken investigate experiments that could put the brakes on the ageing process. Tonight, they examine how much about ageing is luck, and how much is down to genes. #howtostayyoung

Too Fat To Work – Supersized (TV3, 10pm)

It’s a documentary-packed night tonight – this one explores obesity from several perspectives, starting with people who believe that their size is preventing them from getting a job. #supersized

Everybody’s talking about: Sharon Horgan

The Irish actress and writer appeared on Conan last night in the US to promote the second season of Catastrophe, which has just been released across the pond.

Naturally, she was a delight. Watch a snippet of the interview here:

Or flick over for…

• Millionaires’ Mansions (Channel 4, 8pm) Meet the luxury interior designers of London’s elite. 
• Colony (Sky One, 9pm) Lost’s Josh Holloway stars in this new series about a future Los Angeles invaded by ‘outside forces’.
• The Purge (Film4, 9pm) Horror about a dystopian future, where one night a year all crime is legal.
• Happy Valley (RTÉ One, 10.15pm) If you didn’t catch the excellent second series on the BBC, start here tonight.
• Tattoo Fixers (Channel 4, 11.05pm) Awful tattoos, made less awful.