[gmarco]

Thanks all for tips and suggestions.

I was finally able to make it works in this way:

local function HideIt(frame)
    frame:HookScript("OnShow", frame.Hide)
    frame:SetAlpha(0)
    frame:Hide()
end
 
... other code ...
 
if cfg["cleanminimap"] == true then 
 
    -- load the stuff
    LoadAddOn("Blizzard_TimeManager")
    -- zone text
    HideIt(MinimapZoneText)
    HideIt(MinimapCluster.ZoneTextButton)
    HideIt(MinimapCluster.BorderTop)
    -- calendar
    HideIt(GameTimeFrame)
    -- tracking
    HideIt(MinimapCluster.Tracking)
    -- zooms
    HideIt(Minimap.ZoomIn)
    HideIt(Minimap.ZoomOut)
    -- clock
    HideIt(GameTimeFrame)
    HideIt(TimeManagerClockButton)
 
end

I was not able to make it happens during PLAYER_LOGIN event but it was surely something I wrong in the event triggering.

Btw I think AnalogueClock is a very cute addons so'll use it instead

Thanks so muche to everyone... it is really appreciated.