How can i change the hour in my casio rt80 - Shimano Rt80 160mm

To Toggle between 12-hour and 24-hour timekeeping:

In the Timekeeping Mode (regular watch display), press the lower right-hand button to toggle between 12 and 24 hour timekeeping.

You can download the manual from the link below. The information you requested can be found on page 2 (left column).
http://support.casio.com/en/manual/009/qw3768.pdf

You can get instructions from the Casio web site.

Go to the casio web site "casio.com".

Select "support" and the "manuals",
watches;

Accept terms

Select "watch manual archive"

Read the number of the back of your watch and enter it into the search box

mcdevito75 here, Many Casio Watch Models out there, I'll bet however your Casio is displaying say 1 AM rather than 1 PM as it should if the time is indeed PM after 12 noon, if so, this is why the date is changeing at 12 PM rather than, 12 AM simply re-set your casio and make sure the time of day is set at PM for time after 12 noon and AM for time anywhere before 12 NOON. Also, as you set your Casio, look for anything that may give the hint of Military time, this may be revilled as 12 hours or 24 hours, if you have anything like this, make sure it's set for 24 hours. If you have additional problems, visit a small watch repair shop in your area. Again there are many, many Casio models out there and without your watch with me it's difficult to be more accurate.

If you haven't got instructions on how to do this, you can get instructions from the Casio web site.

Go to the casio web site "casio.com".

Select "support" and the "manuals",
watches;

Accept terms

Select "watch manual archive"

Read the number of the back of your watch and enter it into the search box

On the Casio 2747 you can easily change between 12-hour and 24-hour (i.e. Military time)... Follow these steps:

1. Make sure you are in Timekeeping Mode (i.e. digital display shows date at the bottom).
2. Press the "D" button (i.e. bottom-right button) to toggle between 12-hour and 24-hour timekeeping.

Note: 12-hour timekeeping mode will display an "A" or "P" for AM and PM.

http://world.casio.com/wat/download/en/manual/


Use the four numbers on the back of your watch and you will have a PDF version of your instruction manual.

Hope this tip helps

R/

David

Press and hold the top left button for 2 seconds to go into the time adjustment mode.
While you are in this mode press the top right button to switch between 12 hour and 24 hour modes.
Press top left to return to normal.

Follow this link and find out what you want:

http://world.casio.com/wat/download/en/manual/

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