Select "Clock set" from the "Setup" menu, Select the setting item (year, month, date, time, display order, time display format), and set. Press the "Menu/Set" button.
The manual can be found here: http/www.panasonic.co.uk/html/en_GB/Products/DMC-TZ7/Manuals/2032736/index.html The instructions for setting the date and time are on page 15.