Two Papers on Time

Reviewed by Greg Wilson / 2021-09-26
Keywords: Circadian Rhythms, Daylight Savings Time, Productivity

I freely admit that writing short reviews of software engineering research papers is an odd hobby, but surprises like today's other post make it worthwhile, as do gems like the two papers summarized in this post. Hayashi2019 looked at how the shift to and from daylight saving time (DST) affects software development and found that:

  • more DST-related changes are made to software between March and October (the months DST is in effect) than at other times of the year,
  • most DST-related changes are made by developers in countries that observe DST, and
  • the most common way to implement changes is to start using libraries for date and time calculations rather than doing it by hand, presumably because those libraries handle the insanity correctly.

Zavgorodniaia2021 looked at programmers rather than at they code they produce. More specifically, it used keystroke data to determine students chronotypes, i.e., their preferred waking and working hours. After clustering the data, they found four types: those who prefer to work in the morning, to take a break in the middle of the day, to work in the afternoon, and to work in the evening. Chronotype didn't correlate with exam scores for European students, but did for American students, with students who did their work earlier in the day outperforming those who did their work later. They also found that:

…in every chronotype, students in the European context work on their projects at least 25 hours earlier, on average, than students in the US context, and European morning students work fully 50 hours earlier on average. We propose two contextual differences contributing to this effect. The first is the late-work policy. In the US context students could turn in late work for reduced points. In the European context, late work was not accepted. The second factor is project composition. It has been shown that when projects are broken into multiple smaller pieces, students tend to start earlier. Indeed, our results support this conclusion: in the US context the projects are broken into two sub-projects, while the European context has tens of sub-projects due each week.

Finally, this paper found that only 1% of keystrokes occurred between midnight and 5:00 am, from which the authors conclude that the stereotype of "night owl" programmers has little basis in fact.

Hayashi2019 Junichi Hayashi, Yoshiki Higo, Shinsuke Matsumoto, and Shinji Kusumoto: "Impacts of Daylight Saving Time on Software Development". 2019 IEEE/ACM 16th International Conference on Mining Software Repositories (MSR), 10.1109/msr.2019.00076.

Daylight saving time (DST) is observed in many countries and regions. DST is not considered on some software systems at the beginning of their developments, for example, software systems developed in regions where DST is not observed. However, such systems may have to consider DST at the requests of their users. Before now, there has been no study about the impacts of DST on software development. In this paper, we study the impacts of DST on software development by mining the repositories on GitHub. We analyze the date when the code related to DST is changed, and we analyze the regions where the developers applied the changes live. Furthermore, we classify the changes into some patterns.

Zavgorodniaia2021 Albina Zavgorodniaia, Raj Shrestha, Juho Leinonen, Arto Hellas, and John Edwards: "Morning or Evening? An Examination of Circadian Rhythms of CS1 Students". 2021 IEEE/ACM 43rd International Conference on Software Engineering: Software Engineering Education and Training (ICSE-SEET), 10.1109/icse-seet52601.2021.00036.

Circadian rhythms are the cycles of our internal clock that play a key role in governing when we sleep and when we are active. A related concept is chronotype, which is a person's natural tendency toward activity at certain times of day and typically governs when the individual is most alert and productive. In this work we investigate chronotypes in the setting of an Introductory Computer Programming (CS1) course. Using keystroke data collected from students we investigate the existence of chronotypes through unsupervised learning. The chronotypes we find align with those of typical populations reported in the literature and our results support correlations of certain chronotypes to academic achievement. We also find a lack of support for the still-popular stereotype of a computer programmer as a night owl. The analyses are conducted on data from two universities, one in the US and one in Europe, that use different teaching methods. In comparison of the two contexts, we look into programming assignment design and administration that may promote better programming practices among students in terms of procrastination and effort.