In the early 1980s, before we had strip printers in the VCR, our inbound strips were hand-written by our ATSAs. The buff inbound strips would either display the ETA from the stored-flight-plan card, or the time from the FPL telex message.
One morning, I was handed an inbound strip on a British Airwayes 707 inbound from KJFK. The ETA was shown as 1223, taken from the FPL telex signal. I recorded the landing-time, when the main gear touched down as 1223.
As they cleared the runway, I mentioned this to the crew......
"Aces", was the reply I received. Now that WAS a 'Calculated Landing Time'.