Cookie implementation shows questions about the last logon time

Cookie implementation displays the last logon time issue
An account login can display the last logon time, but after changing to another account login,
The logon time displayed is the time of the previous account, do not know what method to solve?
------Solution--------------------
Do you mean to show the last login time?
------Solution--------------------
Or use a database, and if you change a computer, you won't get it.
Of course on a computer, you can use the user's ID to set the cookie key value, after the user login, according to the returned ID to obtain the corresponding cookie
------Solution--------------------
Change the machine, the cookie is not the same, there is no way to synchronize, through the database table storage time, you can solve.
------Solution--------------------
The cookie name with the user ID resolves the issue.

Write cookies
$cookie _name = $uid + ' lastlogintime ';
$cookie _value = time ();
$cookie _expire = time () +31536000;
Setcookie ($cookie _name, $cookie _value, $cookie _expire);

Read cookies
$cookie _name = $uid + ' lastlogintime ';
$lastlogintime = $_cookie[$cookie _name];

