Whaley didn't say it was definitely 12.30pm when Oswald walked towards him did he?
Yes.
https://catalog.archives.gov/id/7461270W aren testimony.
"Mr. BALL. And you put the trip ending Greyhound around 12:30?
Mr. WHALEY. Yes, sir.
Mr. BALL. You remember that trip, do you, you remember the fact that you took the trip to the Greyhound and parked your car at the Greyhound or your cab at the Greyhound, don't you?
Mr. WHALEY. Yes, sir; I remember it.
Mr. BALL. Were you standing at the Greyhound, at your cab stand at the Greyhound, long before you picked up another passenger?
Mr. WHALEY. No, sir, there was no one at the Greyhound stand and when I unloaded at the door I just pulled up about 30 feet to the stand and stopped and then I wanted a package of cigarettes, I was out so I started to get out and I saw this passenger coming so I waited for him. `"