For what you need to do, you don't need loops. You are taking a starting time and a quitting time and calculating the number of hours and the pay - that's all.
You need to do it in two parts: the hour and the minutes.
If the hour is earlier than 1 PM, multiply by 100. For example 8 AM is 800.
If the hour is 1 PM or later, add 2. For example, 1:00 PM is 1300.
After you have converted the hours to 24-hour time, add on the minutes. For example: 8:30 AM becomes 830 and 2:15 PM becomes 1415.
This leads to some difficulties, though, because if someone starts work at 8:30 (830) and works to 2:15 (1415), you might naively calculate the elapsed time as 1415 - 830 = 585, which is incorrect. The actual amount of time is 5 hours and 45 minutes.
To handle this difficulty it might be simpler to convert to hours + decimal part. Using the same times,
8:30 = 8.5
2:15 = 14.25
14.25 - 8.5 = 5.75, which is 5 hours and 45 minutes, the correct elapsed time.
To summarize, after parsing the input string into hour and minutes, convert any times after 1 pm by adding 2, and convert minutes to fractions of hours by dividing the minutes by 60.
For example 4:55 PM = 16.916667 (rounded).
Making the input times strings would make for simpler user input, but more complicated code, since you have to take the string apart and extract the information in it.