On https://www.zabbix.com/documentation/current/manual/api/reference/action/object, the esc_period (both under the Action object and the Action operation) says "Must be greater than 60 seconds." However, 60 seconds appears to work fine, while 59 does not. I think changing the text to either "greater than or equal to 60 seconds", or more simply "at least 60 seconds" would make this more clear.

I did attempt to track this down in the source:

https://git.zabbix.com/projects/ZBX/repos/zabbix/browse/ui/include/classes/api/services/CAction.php#2717

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https://git.zabbix.com/projects/ZBX/repos/zabbix/browse/ui/include/classes/api/services/CAction.php#2838

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The actual check seems to be done here: https://git.zabbix.com/projects/ZBX/repos/zabbix/browse/ui/include/validate.inc.php#586

And since 60 < 60 == false, the check succeeds.