'Estimated period to complete work is surprisingly elastic', this writer interjects

I believe the answer is:

time-scale

I'm a little stuck... Click here to teach me more about this clue!

(Other definitions for time-scale that I've seen before include "Period over which events unfold" , "Duration of, eg, a project" , "Duration allowed for events" .)

I've seen this clue in The Telegraph.

Want a hint initially instead of a full solution? Install my app