How to set 24hr function ?

To change the clock format, visit the General section of Momentum's Settings ??, scroll down to the Clock Format option and then click 12 hour or 24 hour to the right of it. When you switch to the 12-hour format, the AM/PM unit will display for a moment and then fade away to keep the interface clean.
https://get.momentumdash.help/hc/en-us/articles/360022896993-How-can-I-change-the-clock-format-12-hour-24-hour-

https://www.youtube.com/watch?v=VfthmmTM7Oo

Was this problem answered? If yes, can somebody tell me how. My Casio LA670W is in 24hr format and I want it back on 12hr format. My watch have 3 buttons only. Mode, Start-Stop and Timer

this might help. press and hold top right button to change to T1 or time 1. press and hold top left button and u will see ' light on/off' on display. press bottom left button to set chime. press again watch will show 24hr/ 12hr and current time set on watch. 12hr/24hr should be blinking. press top right button to change to preferred hour. press bottom left button to navigate to hour, min,sec use right buttons to select numbers.

Hi, Push the set button and then push the mode switch move the cursor to when it reads 24hr and then select reset and then set button. Hope that helps you.

click on mode or setting option.then you will see the default time.edit it..try to change it using select or any mode available.there you can see 24hr clock and 12 hr clock.select which one you want.if it is in 12 hr then the time will be displaying like eg:7:00am or 7:00pm it means that it is in twelve hours.if it is showing 7:00 or 19:00 it means it is in 24hr clock.

I couldn't find the manufacturers' web site but I found the following , which may help;-

The unit automatically receives the time signal everyday at midnight and makes any required adjustment to the time displayed.

The WAVE OK indicator and the Tower Icon on the display will show if the time signal is successfully received or after manually pressing the SET/WAVE button

You can trigger a Signal Receive operation at any time by pressing the SET/WAVE button, which will activate the Signal Search function of the unit.
To Manually Set the Clock
To Set the Year and Date
1. Press SET/WAVE button after setting TIME ZONE and DST
2. Press + or - button sequentially to set the year (holding down the button will change the year at a high speed)
3. Press SET/WAVE button to confirm the year set and start the date process
4. Press + or - button sequentially to set the current date (holding down the button will change the date at a high speed)
NOTE: The weekday changes automatically depending on the year and date

To Set the Time
1. Press the SET/WAVE button after setting the calendar
2. Press + or - button sequentially to set the minutes (holding down the button will change the year at a high speed)
NOTE: Once you the press + or - button, the seconds will reset to 00

To set the 12/24 HR mode and the Temperature Mode
1. Press SET/WAVE button after setting the time
2. Press the + button to toggle between between 12HR and 24HR (military) modes
3. Press the - button to toggle between C and F temperature display mode
4. Press SET/WAVE button to confirm and quit the set mode

The owner's manual that was sold with it should guide you. If it's missing, get a good hand-lens. Take the watch under a good source of light, and aim the hand-lens to the edges of the watch. You should see 12/24hr button. Press the button once. The time should change from military. If it doesn't , press and hold the shortest button for about 5-seconds. Then press the button that is marked 12/24HR.

Check out the manufacturers web site, some manufactureres have users manuals for their watches which can be downloaded. You may be lucky. You could also try some of the various manuals websites. They have manuals for all manor of things. Good Luck