code: public static long calculateOverdueTimestamp() {
          return Instant.now().toEpochMilli() - getDurationForKey(TenantConfigurationKey.POLLING_TIME_INTERVAL).toMillis()
                  - getDurationForKey(TenantConfigurationKey.POLLING_OVERDUE_TIME_INTERVAL).toMillis();
      }
docs: Calculates the overdue timestamp (<em>overdue_ts</em>) based on the
  current timestamp and the intervals for polling and poll-overdue:
  <p>
  <em>overdue_ts = now_ts - pollingInterval -
  pollingOverdueInterval</em>;<br>
  <em>pollingInterval</em> and <em>pollingOverdueInterval</em> are
  retrieved from tenant-specific system configuration.
  
  @return <em>overdue_ts</em> in milliseconds since Unix epoch as long
  value