[Codger]

Thank you Fizzlemizz!!
I changed the time to a date function and renamed the db file in the toc.

Here is the final code, toc file first:

## Title: MyAddon
## Interface: 100206
## Version: 1.0
## Author: 
## Notes: A simple WoW addon using a database
## SavedVariablesPerCharacter: MyAddonDB
MyAddon.lua

-- Create a saved variable to store last time
local lastLogoffTime = nil
 
-- Create a new frame
local frame = CreateFrame("Frame")
 
-- Load last logoff time from saved variable
local function LoadLastLogoffTime()
    if MyAddonDB then
        lastLogoffTime = MyAddonDB.lastLogoffTime
        print("Last logoff time loaded:", lastLogoffTime)
    else
        print("Trying to load logoff time but MyAddonDB is nil.")
    end
end
 
-- Save last time to saved variable
local function SaveLastLogoffTime(time)
    if not MyAddonDB then 
        print("Trying to save logoff time but MyAddonDB is nil") 
    else
        MyAddonDB.lastLogoffTime = date("%m/%d/%y %H:%M:%S")
    end
end
 
-- Hook the Logout event to update last logoff time
frame:RegisterEvent("PLAYER_LOGIN")
frame:RegisterEvent("PLAYER_LOGOUT")
frame:SetScript("OnEvent", function(self, event)
    if event == "PLAYER_LOGIN" then
        if not MyAddonDB then
            MyAddonDB = {}
            print ("MyAddonDB was nil")
        end
        LoadLastLogoffTime()
    elseif event == "PLAYER_LOGOUT" then
        SaveLastLogoffTime()
    end
end)
 
-- Slash command handler function
local function SlashCommandHandler(msg)
    LoadLastLogoffTime()
end
 
-- Register slash command
SLASH_MYADDON1 = "/myaddon"
SlashCmdList["MYADDON"] = SlashCommandHandler