8 hours seems like way to long to me ... the last one that took you to brells (Mark of Brell) has a recast of 1 hour and 20 minutes.
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Petts 120 Beastlord of Torvonnilous (now on Bertox) Slapau 120 Monk of Torvonnilous (now on Bertox) Cirena 120 Druid of Torvonnilous (now on Bertox) Dohbee 120 Ranger of Bertox
All I know is after casting this several of my other right clickies don't work. My Fabled Journeyman's Boots, Guise of the Deceiver, and other items with no recast type listed.
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Alliance Artisan Demonicspawn Dealerofdeath, Scoundrel of the Oathbreakers Ogre Shadow Knight Vertigo Tunare - The Seventh Hammer
Recast type: 0 is definitely an oversight/bug. The recast type is used to share timers on other items; an example is HoT group chest clickies Type: 16 is the same as UF group chest clickies Type: 16. So if you click your HoT chest, it will be 10 minutes before you can click either your HoT chest OR your Underfoot chest, as they are on the same timer. I imagine this item will be assigned it's own unique Recast Type in a coming patch.
I'm not 100% positive, but I think I tested it out years ago, and as I remember, it's used to share timers, so that any click effect with the same recast type, will not work until the current timer is up.
EDIT: After reading your other post, it may be that the 0 recast type is a bug or error, as most non-clickies use 0 for recast type, and only one (Edit: Non-instant) clicky item other than this uses 0 recast type, and only has a 2sec recast timer.