My father in law has an old Casio model 548 wrist watch. It's stuck in military time and he wants to reset the time to a 12 hour option and move into daylight savings time. Can you help?

SOURCE: How do I set the 12 or 24 hrs setting on my Casio DW 9052 casio?

when you are setting the time just hit the (g) or light button and it will switch it to 2400 time.

SOURCE: Daylight Saving Time will not set correctly

Use this page to download a copy of CASIO watch manuals in PDF format. To download a PDF file, enter the four-digit (or three-digit) module number marked on the back cover of your watch.

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

You will need a pdf reader on your pc, you will find all instructions in there.

If you don't have a pdf reader you can get one from
http://www.foxitsoftware.com/pdf/rd_intro.php

SOURCE: Help setting the time

Tags have a screw down crown (winder knob) turn the knob counter clock-wise until you feel the crown unscrew (not off) then pull the crown carfully. It will pop once this is for date adjust. Then pull once more and you can now adjust the hands, set accordingly then push crown back in. After you push it back in gently compress the crown and tighten clockwise until it stops. CAUTION!!!!!!! Tags are not waterproof if the crown is not screwed back down. I hope this helps I am actually a car guy (just happen to own a couple)

SOURCE: changing analog hands / time function due to daylight saving time

Download the manual from
http://ftp.casio.co.jp/pub/world_manual/wat/en/qw2747.pdf

SOURCE: cannot change from 24 hour to 12 hour

To change from 24 hour to 12 hour, you hold down the "Mode" button until it switches from 24 hour to 12 hour or vice versa. To change the time zone, you hold down the "Set" button until the time zone that you set it in flashes (like "LAX" on my watch). Then you press the "Receive/Start/Stop" button to choose the specified time zone you want. To set for daylight savings time ("DST" on the watch), after holding the "Set" button and having the time zone flash, you could press the "Mode" button. It will give you a few options for the daylight savings time (Auto, On, or Off). I chose the "On" option, which immediately changed for daylight savings time. If you manually want to change the time, you could hold down the "Set" button and keep pressing the "Mode" button until the time starts flashing on your watch, then pressing the "Receive/Start/Stop" button until you change it to the time that you want. You could also set the watch to beep or chime after pressing the set button if you wanted to know that piece. You hold down the "Set" button when you are done to get it to stop flashing. These instructions worked for my Timex T5G341 Universal Radio Control Watch. I hope this helps.