This is my class:
package com.tools.app.holiday; public class Holiday { private String name; private Calendar dateFrom = Calendar.getInstance();
According to ProGuard documenation the wildcard <fields> matches any field. Thus it should be something like:
<fields>
-keepclassmembers class com.tools.app.holiday.Holiday { private <fields>; }
If you want to preserve private fields in all classes use:
-keepclassmembers class * { private <fields>; }