Position affects space and time (6)
I believe the answer is:
aspect
'position' is the definition.
(thesaurus)
'affects space and time' is the wordplay.
'affects' indicates anagramming the letters (I've seen 'affected' mean this).
'and' is a charade indicator (letters next to each other).
'time' becomes 't' (abbreviation).
'space' with letters rearranged gives 'aspec'.
'aspec'+'t'='ASPECT'
(Other definitions for aspect that I've seen before include "Viewpoint, feature to be considered" , "Look; side of building" , "particular view" , "Particular part or feature of something" , "Face" .)