Reference

bson_append_date_time(3) on Linux

The text 41dbb6152ced, as Debian 9 (Stretch) shipped it.

The bson_append_date_time() function shall append a new element to a bson document containing a date and time with no timezone information. value is assumed to be in UTC format of milliseconds since the UNIX epoch. value MAY be negative.

bson_append_date_time(3) on Linux now