On most or all of the Aquatech models there should be a light button plus three others, marked mode, start/stop, and lap/reset.
To set time and date etc.: Starting with the watch set on the time (if not already, use the mode switch until the time shows),
Push the mode button 3 times ...
Then use the lap/reset button to advance through each of the items (minutes, hour, date, month, day of week). When on each of them, you can push the start/stop button to advance through the details (minutes, hours, etc.).
When on the hour setting, it advances through 12-hr AM (A), 12-hr PM (P), or 24-hr (H). If you keep going, it just recycles back through. Switching between 12 hr and 24 hr (military) systems is done as part of the settings for time and date.
Whenever you have everything set the way you want it, just push the mode button and it goes back to normal time keeping.
To turn off the hourly beep: While holding the lap/reset button down, press the mode button. When all 7 day flags show, the hourly chime is on. When no day flags show, the chime is off.
For the alarm: If you want to use it (I think both it and the light use battery faster than when not used), you set it by pushing mode button twice, as indicated above, then go to hour or minute setting by pushing the lap/reset button, and advance to the time you want by pressing the start/stop button. Pushing mode will take you back to normal time again.
To turn alarm on or off, hold lap/reset button in and at the same time push the start/stop button. Alarm icon will show on or off. When you release the lap/reset button, it will revert to normal time.
If the alarm is on, at the designated time it will start beeping for awhile or until the lap/reset button is pushed (off) or start/stop button (snooze).