Internally, dates and times are represented relative to the UNIX epoch, in which time "zero" corresponds to the stroke of midnight on January 1, 1970 in UTC time, which runs along the prime meridian. It turns out there are a few movies with missing (
null) release dates. Those
null values get interpreted as time
0, and thus map to January 1, 1970 in UTC time. If you live in the Americas – and thus in "earlier" time zones – this precise point in time corresponds to an earlier hour on December 31, 1969 in your local time zone. On the other hand, if you live near or east of the prime meridian, the date in your local time zone will be January 1, 1970.