GE JE320 Owner's Manual page 16

About the time feature.
16
Setting Cooking Time
Allows you to microwave for any time up to 15 minutes.
Press Time + once for each minute of cooking time
1
desired.
Press Time – once for seconds of cooking time
2
desired.
After 5 seconds, the oven will start and the cooking
3
time will count down in the display.
Once cooking has begun, pressing the Time +
or – pad will increase or decrease cooking time
by 10 seconds.
You may open the door during cooking to check
the food. Close the door and press Time + or – to
resume cooking.