From the manual: To set the Time. 1. PRESS the [Select] button and hold in for 2 seconds. Located in Field 3, the seconds will begin to flash 2. PRESS the [+] button to scroll the seconds upward or PRESS the [-] button to reset the seconds to zero. 3. At the seconds desired, PRESS the [Select] button to move to the next setting. Located on right of Field 2, the minutes will begin to flash. 4. PRESS the [+] button to scroll the minutes upward or PRESS the [-] button to scroll the minutes downward. 5. At the minutes desired, PRESS the [Select] button to move to the next setting. Located in the center of Field 2, the hour will begin to flash. 6. PRESS the [+] button to scroll the hour upward or PRESS the [-] button to scroll the hour downward. 7. At the hour desired, PRESS the [Select] button to move to the next setting. Located in Field 1, the 24 or 12 hour clock setting will begin to flash. 8. PRESS either the [+] or the [-] button to toggle between the 24hr and 12hr. Choose either AM/PM for 12hr. 9. At the clock setting desired, PRESS the [Select] button to move to the next setting. Located in the center of Field 2, the year will begin to flash. 10. PRESS the [+] button to scroll the year upward or PRESS the [-] button to scroll the year downward. 11. At the year desired, PRESS the [Select] button to move to the next setting. Located in the center of Field 3, the month represented by a number will begin to flash. 12. PRESS the [+] button to scroll the month upward or PRESS the [-] button to scroll the month downward. 13. At the month desired, PRESS the [Select] button to move to the next setting. Located to the right of Field 3, the date will begin to flash. 14. PRESS the [+] button to scroll the date upward or PRESS the [-] button to scroll the date downward. Note: Once the user has determined the year, month and day, the Wristop Computer will supply the day of the week in Field 1. The American month/day -view can not be changed to a day/month -view. 15. At the desired date, PRESS the [Mode] button to accept the changes and return to the main mode. Note: If the user does not press any button for 1 minute in the setup mode, the display will automatically exit setup. Setting the time is now complete You can download the complete manual here: http://www.suunto.com/suunto/main/article_1column.jsp?CONTENT%3C%3Ecnt_id=10134198673939084