Definition: In this task, based on the given input, we ask you to write a question about when an event happened. Your question should be answerable with common knowledge on when events usually take place. For example, "going to school" usually happens during the day (not at 2 A.M). Don't create questions which have explicit mentions of answers in the text. Instead, it has to be implied from what is given. In other words, we want you to use "instinct" or "common sense". The written questions are not required to have a single correct answer.
Input: Sentence: By 1930 raw-material production had tripled the figure of 1900, manufactured goods had increased twelve-fold, and heavy industry was galloping towards maturity.
Output:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
At what time of the day was manufacturing occurring?