The at time <time> context corresponds to the 3ds Max time slider. Any animatable property references will yield their interpolated values for the specified time. If the Animate button is on, or the script is also in an animate on context, keyframes are generated at the specified time when an animatable property of a 3ds Max object is changed.
Setting an at time context does not affect the 3ds Max time slider. The time associated with the time slider can be queried and set using the sliderTime global variable.
-- generate a keyframed animation of $foo randomly chasing $baz
for t in 0 to 100 by 5 do
at time t
$foo.pos = $baz.pos + random [-10,-10,-10] [10,10,10]