Time short after worker has a fit (7)
I believe the answer is:
Here is my best explanation:
'a fit' is the definition.
('tantrum' can be a synonym of 'fit')
'time short after worker' is the subsidiary indication.
'time' becomes 't'.
'short' becomes 'rum' (short can mean an alcoholic drink**).
'after' is a charade indicator (letters next to each other).
'worker' becomes 'ant'.
'rum' after 'ant' is 'antrum'.
'has' is the link.
(Other definitions for tantrum that I've seen before include "Spoilt brat's fit", "Childish angry outburst", "Angry outburst", "Burst of temper", "Hissy fit", "Fit of childish rage", "Child's outburst of bad temper", "Temper outburst", "Fit - pet" and "Pet, temper".)