Hi there! We always start earlier and earlier as Christmas gets closer, just more volume. You'll get paid for it.
You can change your start time on the clock. Enter your code and it will show your start time. Use the arrow forward key to advance and change the numbers on the time, just like a computer. Also tell a full time supervisor (not a pt) that you had to change your start time on the clock and make sure it will be changed in their records. If you can't change the time yourself, tell them that also.
There should be a manual time clock in the building. The old punch type machine. If you don't see it, ask where it is. Take a piece of paper and punch yourself in before usiing the electronic clock. At the end of your shift, punch out on the electronic one first, then on the punch clock. Keep that piece of paper as proof of your hours. It will have the date and time on it. Many of us do that every single day to make sure our pay is correct. Someone else in this forum may have other suggestions.
UPS is the land of screwed up paychecks. Sometimes it's a pain in the rear to get it straightened out. Even though you're not in the union ask a steward about the situation. He/she should be glad to help you. If, for some reason you don't get help there, find a seniority employee who is friendly and ask them about it.
Hope you can get the help you need and your paychecks are correct. Take good care, happy peak and come back here if you have more questions.