In article <
2ebe9e1f-7da5-4302...@googlegroups.com>,
From the abovegiven URL:
--begin quoted text:
Coders chose 1920 to 2020 as the standard window because of the
significance of the midpoint, 1970. "Many programming languages and
systems handle dates and times as seconds from 1970/01/01, also called
Unix time," says Tatsuhiko Miyagawa, an engineer at cloud platform
provider Fastly.
--end quoted text
Most systems I worked on used a CENTWIN of 45.
DD