@Override
    protected StateFactory init(ExpressionExecutor[] attributeExpressionExecutors, ConfigReader configReader,
                                SiddhiQueryContext siddhiQueryContext) {
        if (!(attributeExpressionExecutors.length == 0 || attributeExpressionExecutors.length == 1)) {
            throw new SiddhiAppValidationException("incrementalAggregator:getTimeZone() function " +
                    "accepts zero or one argument, but found " + attributeExpressionExecutors.length);
        }
        if (attributeExpressionExecutors.length == 1) {
            if (attributeExpressionExecutors[0].getReturnType() != Attribute.Type.STRING) {
                throw new SiddhiAppValidationException("Time zone can be retrieved, only from " +
                        "string values, but found " + attributeExpressionExecutors[0].getReturnType());
            }
        }
        return null;
    }
Executor class for retrieving the timezone from a string timeStamp.
modules/siddhi-core/src/main/java/io/siddhi/core/executor/incremental/IncrementalTimeGetTimeZone.java