-- Basic trigger-time tests for cron_utils
CREATE EXTENSION cron_utils;
SET timezone = 'UTC';
-- next daily midnight trigger on/after 2024-01-01 12:00
SELECT cron_first_trigger('0 0 * * *', '2024-01-01 12:00+00');
      cron_first_trigger      
------------------------------
 Tue Jan 02 00:00:00 2024 UTC
(1 row)

SELECT cron_first_trigger('0 0 * * *', '2024-01-01 00:00+00', strict => true);
      cron_first_trigger      
------------------------------
 Tue Jan 02 00:00:00 2024 UTC
(1 row)

-- last weekday 9am trigger on/before 2024-01-08 00:00 (Sunday -> Friday)
SELECT cron_last_trigger('0 9 * * 1-5', '2024-01-08 00:00+00', strict => true);
      cron_last_trigger       
------------------------------
 Fri Jan 05 09:00:00 2024 UTC
(1 row)

-- first/last triggers within a window
SELECT * FROM cron_first_last_triggers(
    '0 0 * * *',
    '2024-01-01 00:00+00',
    '2024-01-31 23:59+00'
);
            first             |             last             
------------------------------+------------------------------
 Mon Jan 01 00:00:00 2024 UTC | Wed Jan 31 00:00:00 2024 UTC
(1 row)

-- step expression: every 15 minutes
SELECT cron_first_trigger('*/15 * * * *', '2024-01-01 00:07+00', strict => true);
      cron_first_trigger      
------------------------------
 Mon Jan 01 00:15:00 2024 UTC
(1 row)

-- multiple triggers
SELECT cron_iterate_n('0 * * * *', '2024-01-01 00:00+00', false, 'next', 3);
        cron_iterate_n        
------------------------------
 Mon Jan 01 00:00:00 2024 UTC
 Mon Jan 01 01:00:00 2024 UTC
 Mon Jan 01 02:00:00 2024 UTC
(3 rows)