Jack, Dan and Jamie will be on air non-stop for 24 hours to raise money and awareness for local hospice Nightingale House.
They'll be chatting to staff from the hospice to find out more about what goes on there, local fundraisers and even a performance from the choir!
We also have live acoustic performances from Ste Jones and Ben Hands, who will be playing at the Llwyn Isaf bandstand as part of Focus Wales.
Overnight, they will even tackle the Ladies Midnight Walk on a treadmill in the studio!
Tune in on 105fm, or online at ww.calonfm.com to hear how they get on.