One of the things I do professionally is helping researchers organise and preserve their data. This can involve thinking through the best formats to use to represent data and understanding how different software interprets those formats. This can be a particularly thorny issue when it comes to date formats, especially in the case of the very commonly used software, Microsoft Excel. But date formats aren’t even the half of it when we start thinking about the cultural complexities of communicating and interpreting different systems for thinking about and encoding time.
I often introduce the topic of date formats in relation to file naming. Dates can be useful information to have in the title of a file: the date a sample was collected, interview conducted, etc. Because there are so many different ways of writing dates, it’s important to choose a consistent date format when establishing file naming conventions. Is 01/03/1998 the 1st of March or the 3rd of January 1998? Is 200405 May 2004 or 5th April 2020? There is an international standard that recommends which date format to use: ISO 8601 (eg. YYYY-MM-DD). This has the advantage of sorting in date order in most file systems, which isn’t true of other date formats.
Under the hood, Microsoft Excel encodes dates, or any data it interprets as a date, as a numerical value, which can be displayed in a variety of date formats. This has the unfortunate of effect of corrupting genomic and other data opened in Excel, as well as converting ISO 8601 formatted dates into various other formats, as discussed by De Rijk, D’Hert, and Strazisar in their pre-print opentsv prevents the corruption of scientific data by Excel:
Ironically, not even dates are completely safe: An unambiguous iso 8601 conformant date such as 2018-02-04 is converted to an ambiguous, locale dependent format (2-4-2018 or 4-2-2018) upon export (Kosmala, 2016). A date where only the month and year are indicated (e.g. april 2001) will be changed to apr-01, which can, after export, be easily confused with the first of April instead.
As a Jew, I not only have to a consider the date format, I also have to consider the calendar system I’m using. The date of this post, for example, is 2020-08-09 in the Gregorian calendar, and 5780-05-20 in the Hebrew calendar. To add an extra layer of complexity, days in the Hebrew calendaring system start at sundown. I’m posting this at 21:33pm on Sunday evening. The 20th Av (Av is the fifth month of the Hebrew year) runs from sundown on Sunday through to sundown on Monday and would typically be shown on calendars as occurring on the Monday. (An extra trivia tidbit: the Jewish new year, Rosh HaShanah, takes place on 1st Tishrei, the seventh month of the Hebrew year, not the first day of the first month, Nisan.) I have the Hebrew calendar switched on as an alternate calendar in Google calendar, export significant dates from HebCal and import them as appointments into Google calendar, and also use a print calendar displaying candle lighting and other ritual timings for festivals and other days when we’re not permitted to use devices or the internet.
Following a different calendar also means having a different qualitative sense of time and keeping a different temporal rhythm than the rest of the secular or culturally Anglo-Christian world. My weeks are punctuated by Shabbat, the Jewish Sabbath and day of rest. This is one of the days on which there are a number of restrictions on activities that can be performed, such as using devices and doing other forms of work. Shabbat falls on a Saturday, and because Hebrew days start at sundown, this means Shabbat starts on Friday evenings. It begins and ends earlier in the winter, when it gets dark sooner, and later in summer, when the sun stays up for longer. As a result, I have to leave work early on Fridays in the winter and can never make it to Friday night drinks or professional development events that are scheduled for Friday evenings or Saturdays.
The Jewish High Holydays usually fall around September or October. I often have to take annual leave in order to observe these festivals and there have also been times when the High Holydays have coincided with professional conferences I would have liked to attend. One year I was scheduled to present a conference paper on Yom Kippur, the day of atonement, until I contacted the conference organisers to get the presentation rescheduled. Fortunately, the conference hotel was within walking distance of a synagogue, and I was able to attend the conference the day before Yom Kippur, observe the fast day itself, and then attend the final day of the conference and give my presentation. Meanwhile, when things shut down over the Christmas period, I’m often left at a bit of a loose end.
Because of these sorts of experiences, it’s important for me to keep track of various religious holidays, both in my personal life (people close to me follow the Persian, Chinese, and Islamic calendars) and professional life. If I’m scheduling events and training sessions, for example, I want to make sure I’m not scheduling them on someone else’s religious holiday. One way I’ve found of doing this is to add religious holidays to my work Outlook calendar and personal Google calendar. I also try to keep an eye on things like the Harmony Week calendar of cultural and religious dates, even though it’s only kept updated for one year at a time.
There’s so much that gets taken for granted in the way we think about time. To really understand the Hebrew calendar and why it is the way it is, you need to understand so much about the Jewish religion and worldview. Why does Jewish new year fall at the start of the seventh month instead of the first? Well, short answer, because it says so in the Torah (first five books of the Hebrew Bible). But many longer, more complex answers to that question have been given by scholars over the years, interpreting and theorising the reasons and meanings. The calendar is tied to natural rhythms: the daily cycle of the sun rising and falling, lunar cycles, the annual cycle the seasons, weather patterns. These rhythms are tied to Jewish ritual: daily prayer times, the celebration of Rosh Chodesh (the start of the new lunar month), the annual Jewish festivals that may be tied eg. to harvest time, changes in prayers according to weather patterns due to the time of year. I’m not really doing this justice, but hopefully you get what I mean.
I guess what I’m saying is: behind every date, there’s a calendar. Behind every calendar, there’s a culture. And beyond even that, there are many more cultures than there are calendars, each with their own conception of time. Whenever we interact with another person, we’re subtly translating how we understand and perceive time. Sometimes that translation means we keep someone waiting or we rush someone when we didn’t mean to. Sometimes it means we schedule an event on someone else’s holy day. Sometimes it means the software we use converts an ISO 8601 date format into a different date format and confusion results. The best we can do is be conscious of how we ourselves perceive time, choose our formats wisely, and be aware of how the software we use functions.