-'error.db' => 'chyba databáze',
-'error.field' => 'nesprávná "{0}" data',
-'error.empty' => 'pole "{0}" je prázdné',
-'error.not_equal' => 'pole "{0}" neodpovídá poli "{1}"',
-'error.interval' => 'nevhodný interval',
-'error.project' => 'výběr projektu',
-'error.activity' => 'výběr činnosti',
-'error.auth' => 'nesprávné jméno nebo heslo',
-// Note to translators: this string needs to be translated.
-// 'error.user_exists' => 'user with this login already exists',
-'error.project_exists' => 'projekt tohoto jména již existuje',
-'error.activity_exists' => 'činnost tohoto jména již existuje',
-// TODO: translate error.client_exists.
-// 'error.client_exists' => 'client with this name already exists',
-// Note to translators: error.no_login needs to be properly translated (e-mail replaced with login).
-// 'error.no_login' => 'uživatel s tímto e-mailem neexistuje',
-'error.upload' => 'chyba přenosu souboru',
-// Note to translators: these 5 strings are missing from the translation and must be added.
-// 'error.period_locked' => 'can\\\'t complete the operation. records older than a certain number of days cannot be created or modified. team manager defines this in the "Lock interval in days" value on the "Profile" page. set it to 0 to remove locking. <br><br>uncompleted records (with 0 or empty duration) can be deleted.',
-// 'error.mail_send' => 'error sending mail',
-// 'error.no_email' => 'no email associated with this login',
-// 'error.uncompleted_exists' => 'uncompleted entry already exists. close or delete it.',
-// 'error.goto_uncompleted' => 'go to uncompleted entry.',
-
-// labels for various buttons
+'error.db' => 'Chyba databáze.',
+'error.field' => 'Nesprávná "{0}" data.',
+'error.empty' => 'Pole "{0}" je prázdné.',
+'error.not_equal' => 'Pole "{0}" neodpovídá poli "{1}".',
+// TODO: translate the following.
+// 'error.interval' => 'Field "{0}" must be greater than "{1}".',
+'error.project' => 'Výběr projektu.',
+// TODO: translate the following.
+// 'error.task' => 'Select task.',
+// 'error.client' => 'Select client.',
+// 'error.report' => 'Select report.',
+// 'error.record' => 'Select record.',
+'error.auth' => 'Nesprávné jméno nebo heslo.',
+// TODO: translate the following.
+// 'error.user_exists' => 'User with this login already exists.',
+'error.project_exists' => 'Projekt tohoto jména již existuje.',
+// TODO: translate the following.
+// 'error.task_exists' => 'Task with this name already exists.',
+// 'error.client_exists' => 'Client with this name already exists.',
+// 'error.invoice_exists' => 'Invoice with this number already exists.',
+// 'error.no_invoiceable_items' => 'There are no invoiceable items.',
+// 'error.no_login' => 'No user with this login.',
+// 'error.no_teams' => 'Your database is empty. Login as admin and create a new team.',
+'error.upload' => 'Chyba přenosu souboru.',
+// TODO: translate the following.
+// 'error.range_locked' => 'Date range is locked.',
+// 'error.mail_send' => 'Error sending mail.',
+// 'error.no_email' => 'No email associated with this login.',
+// 'error.uncompleted_exists' => 'Uncompleted entry already exists. Close or delete it.',
+// 'error.goto_uncompleted' => 'Go to uncompleted entry.',
+// 'error.overlap' => 'Time interval overlaps with existing records.',
+// 'error.future_date' => 'Date is in future.',
+
+
+
+// TODO: refactoring ongoing down from here.
+
+// Labels for buttons.