@Test
  public void test_jdbc_customization_supports_timestamps_in_utc() {
    Optional<JdbcCustomization> jdbcCustomization = getJdbcCustomizationForUTCTimestampTest();

    if (jdbcCustomization.isEmpty()) {
      LOG.info(
          "Skipping test_jdbc_customization_supports_timestamps_in_utc since to JdbcCustomization is spesified.");
      return;
    }
    LOG.info(
        "Running  test_jdbc_customization_supports_timestamps_in_utc for: "
            + jdbcCustomization.get().getName());

    TaskResolver defaultTaskResolver =
        new TaskResolver(SchedulerListeners.NOOP, new SystemClock(), List.of());
    defaultTaskResolver.addTask(oneTime);

    JdbcTaskRepository taskRepo =
        createRepositoryForJdbcCustomization(defaultTaskResolver, jdbcCustomization.get());

    ZonedDateTime zonedDateTime =
        ZonedDateTime.of(2020, 1, 1, 12, 0, 0, 0, ZoneId.of("Europe/Oslo"));

    TaskInstance<String> instance1 = oneTime.instance("future1");
    taskRepo.createIfNotExists(SchedulableInstance.of(instance1, zonedDateTime.toInstant()));

    assertThat(taskRepo.getExecution(instance1).get().executionTime, is(zonedDateTime.toInstant()));
  }
Very uncertain on how to verify that the timestamp is stored in UTC. The asserts in this test
will likely always work, but at least the code for storing in UTC is exercised.
db-scheduler/src/test/java/com/github/kagkarlsson/scheduler/compatibility/CompatibilityTest.java