Short for a modified half day off in which a rostered half day off is "modified" to include the rest of the same day culminating in a full day off.
Not to be confused with the "Super Halvie", a rumored to be mythical creation in which one takes the Friday afternoon halvie and the consecutive Monday morning allowing the "halver" to enjoy a partial long weekend.
J-Dizzle: "Happy Thursday afternoon Phantom, are you taking the modified halvie tomorrow?"
Phantom: "Well a good morning to you too J-Dizzle! I am indeed taking the modified halvie tomorrow!"
J-Dizzle: "You aren't attempting a super-halvie are you? They're only in fairytales and J-HO Surg aren't they?"
Phantom: .....