It will be a clock - a digital clock- it will accidentally have been set into a delayed timer mode - this is what to do....
Turn the mains power off and then on again so that the clock flashes...
Depress and hold in buttons 2&3 from the left
Use the plus and minus buttons to set the time - any time will do the cooker doesn't care.
Now your'e cooking on gas - or electricity - you do not mention the make or model of your appliance...
Good Luck..., September 2016