Clock setting? Endless fluster one observed around Middle East (4,4)
I believe the answer is:
time zone
'clock setting?' is the definition.
'endless fluster one observed around middle east' is the wordplay.
'endless' means to remove the last letter.
'fluster' becomes 'tizz' (both can informally mean an agitated state).
'observed around' indicates putting letters inside.
'middle east' becomes 'me' (abbreviation for Middle East).
'tizz' with its last letter taken away is 'tiz'.
'tiz'+'one'='tizone'
'tizone' placed around 'me' is 'TIME-ZONE'.
(Other definitions for time zone that I've seen before include "it changes from east to west" , "Region where clocks show the same hour" , "Longitude-related area" .)