Try-except statement not working in while loop

I wrote a program with the function convert_12_to_24 to convert 12hr time to 24hr time, however, the times were only defined in the program, and did not accept user input. I decided to upgrade the code by allowing the user to input a specific time for output and used a try-except statement to check for errors in user input.

def convert_12_to_24(hour,minute,meridiem):
    if (hour == 12) and (meridiem == 'PM'):
        print("12:" + str(minute))
    elif (hour == 12) and (meridiem == 'AM'):
        print("0:" + str(minute))
    elif (meridiem == 'PM'):
        hour_1 = int(hour) + 12
        print(str(hour_1) + ':' + str(minute))
    elif (meridiem == 'AM'):
        print(str(hour) + ":" + str(minute))

hour = input("Hour: ")
minute = input("Minute: ")
meridiem = input("AM or PM: ")

while True:

    try:
        convert_12_to_24(hour,minute,meridiem)
        break

    except:
        print("\n")
        print("Error, please input in the following manner: ")
        print("Hour: XX")
        print("Minute: XX")
        print("AM or PM: AM or PM")

However, when I run the code, the code doesn't rerun with an error, and the order of execution for the function conditionals is messed up. Any help would be appreciated.

I have modified your code:

hour and minute should be converted to int type when asking user input

If any of the conditions are not matching I am raising an error by returning 1/0 so the code falls back to except in try-except block.

def convert_12_to_24(hour,minute,meridiem):
    if (hour == 12) and (meridiem == 'PM'):
        print("12:" + str(minute))
    elif (hour == 12) and (meridiem == 'AM'):
        print("0:" + str(minute))
    elif (meridiem == 'PM'):
        hour_1 = int(hour) + 12
        print(str(hour_1) + ':' + str(minute))
    elif (meridiem == 'AM'):
        print(str(hour) + ":" + str(minute))
    else:
        return 1/0

hour = int(input("Hour: "))
minute = int(input("Minute: "))
meridiem = input("AM or PM: ")

while True:

    try:    
        convert_12_to_24(hour,minute,meridiem)
        break

    except:
        print("\n")
        print("Error, please input in the following manner: ")
        print("Hour: XX")
        print("Minute: XX")
        print("AM or PM: AM or PM")
        break