Please read the user preferences documentation especially the part about timezones.
Don’t mix it up with the system specific configuration for new customers.
If you try to create a user and see an error message like The email is already used
or The username is already used
it is very likely, that this account was deactivated in the past. Deactivation does not remove a user from Kimai,
it just hides it from all views and listing.
You can reactivate the account by going to the User administration, open the
search and choose the value Both
or No
for the search option Active
. The resulting list will include all
deactivated users which can be reactivated by editing them and checking the Active
checkbox.