It’s close at work —a special day (8)
I believe the answer is:
solstice
'a special day' is the definition.
(eg the Winter Solstice)
'it's close at work' is the wordplay.
'at work' is an anagram indicator.
'its'+'close'='itsclose'
'itsclose' is an anagram of 'SOLSTICE'.
(Other definitions for solstice that I've seen before include "it occurs biannually" , "Time of highest or lowest noon sun" , "Time of year when sun is furthest from equator" , "Midsummer or midwinter point" , "When night and day are most unequal" .)