async getLastNonOpenedEventTimestamp() {
        return this.#fetchLatestNonOpenedData?.lastEventTimestamp ?? (await this.queries.getLastEventTimestamp(this.#fetchLatestNonOpenedData.jobName,['delivered','failed'])) ?? new Date(Date.now() - TRUST_THRESHOLD_MS);
    }
Returns the timestamp of the last non-opened event we processed. Defaults to now minus 30 minutes if we have no data yet.