Correction: I saw this sentence in a the text book. It said "Gone are the days when we are asked to complete the work in a forty minute class." The beginning "Gone should be the days..." confused me. Does it mean "this circumstance was past"? Also, could you explain the grammar used in "Gone should be the days..." The expression should be "Gone are the days when......"= the days have long gone when....../the days have passed when....../ the time has passed when....

*cited. -Not quite. It's a more emphatic, poetic way to say "the days when we are asked to complete the work in a forty minutes class" should be gone/ in the past (but they aren't); someone is expressing their opinion/wish that those days be gone/in the past, but they are still happening.