What is "every hours" trigger of Mass actions

-- HikaShop version -- : 2.3.5
-- Joomla version -- : 3.3.6
-- Browser(s) name and version -- : latest IE, FF and Chrome

How do I know at what time it triggers.
Is it for example 13:00 14:00 and so on or is every hour after saving the event?

Kind regards,

Wilfried

Hi,

Is it every hour after saving the event.

Great thanks.