Mistake on Manhattan guide?

[jimmy0397]

On page 87 of the SC guide (new version), it says "in which" can be used to modify time.

But on page 717 of og 13 question 35 answer d explanation stated that the correct pronoun for time is "when".

Thoughts?

[tim]

"in which" can modify a time *period*, but not a time:

i can say the 18th century was a time period in which a lot of historical changes occurred, but i cannot say that 5:00 is a time in which i eat dinner..