Intense time being accommodated by former engineers (7)
I believe the answer is:
Here is my best explanation:
'intense' is the definition.
('extreme' can be similar in meaning to 'intense')
'time being accommodated by former engineers' is the subsidiary indication.
'time' becomes 't'.
'being accommodated by' is an insertion indicator.
'former' becomes 'ex'.
'engineers' becomes 'reme' (I've seen this in other clues).
't' put into 'exreme' is 'extreme'.
(Other definitions for extreme that I've seen before include "Ultimate", "immoderate", "Far beyond the norm", "Drastic; outermost", "Going to great lengths", "Farthest - to the highest degree", "Most violent", "Exceptional; very great", "Unrestrained" and "Going beyond moderation".)