"I'm going to do this for the next 75 days, no matter what the fuck happens," he says. "If i say i wan to do it, if i post my day on it's over." He adds: 'It doesn't matter how tired you are, it doesn't mattr how long it takes' The full interview will be aired at 8pm tonight (UK time) and 9pm tomorrow night (UK time). For more information visit www.bbc.co.uk/josiah or follow Josiah on instagram @josiah_says.