The old Queen managed day job (6)
I believe the answer is:
errand
'job' is the definition.
(thesaurus)
'the old queen managed day' is the wordplay.
'the old queen' becomes 'ER' (Elizabeth Regina, ie Queen Elizabeth).
'managed' becomes 'ran' (both can mean organised or was in charge of).
'day' becomes 'd' (abbreviation for day).
'er'+'ran'+'d'='ERRAND'
(Other definitions for errand that I've seen before include "Task, message" , "Journey to deliver message etc" , "In purposeful trip" , "Short trip with a mission" , "Commission, task" .)