Festina is a watch company based in Barcelona, Spain. The company was founded in La Chaux-de-Fonds, Switzerland but since a takeover its watches' internal components, known as "movements," have been manufactured by Citizen Watch Company in Japan. Since the F16095/4 watch does not know the month - the date display advances to "31" every time meaning you have to adjust the watch on the first of every month. Setting the date on your Festina F16059/4 ensures you always have the correct day of the month at hand.
Locate the "Crown" dial on the right side of the watch, beside the date display.
Pinch and lift the crown, it will click once.
Turn the crown counterclockwise. The date display starts moving.
Spin the crown until the correct date appears. Numbers 1 to 31 move through the viewing window. Stop when today's date is showing.
Turn the crown clockwise until the correct day of the week appears. The days of the week cycle through the viewing window while the crown is turning.
Push the crown back down so it sits against the body of the watch. The date is set. Repeat these instructions at the start of every month -- the Festina F16059/4 counts to 31 each month regardless of the number of days.
Set the time on your F16059/4 first -- the date ticks over at midnight which is easily confused with midday when the time is not set properly.