This static method takes a standard Python datetime instance and returns a new SiderealTime instance representing the
corresponding Greenwich Sidereal Time.
SiderealTime.fromDatetime(dt)
The argument is a datetime instance. If
dt is an “aware” timestamp
instance, with time zone information, the result
represents the sidereal time at the equivalent UTC
corresponding. If dt is
“naive,” with no time zone information, it
is assumed to represent UTC.