I require assistance for a countdown timer in a GUI.

Hello, recently I have been attempting to make a bomb with a GUI containing a timer that counts down to 0 when a button is pressed, my problem here is getting that timer to work. Is there any way possible to make a working countdown timer in the GUI for my bomb? My thought was that there was a way to make a text label change but that doesn't seem to be possible (keep in mind, I'm a bit new to MCreator so there might be some things I don't know).