Timezone Pissing contest

Andrew was moaning about timezones, and I just had to chip in.

Further to all that, imagine having a product running on almost every known UNIX variant, accepting data from almost every known field device. The data contains a timestamp, and a number that represents an hourly average for gas pressure. Now, is that top of the hour or bottom of the hour? What timezone is the field device in? What timezone are the servers in? What timezone is the user going to be in? Does the user want to show the data in his local timezone, or the timezone of the field device? What happens when all the states switch to daylight saving at different times? What happens if the field devices and the host servers get out of sync?

These hourly records get aggregated into daily records. Is that top of day or bottom of day? When is the day boundary? Midnight? 6AM? 8AM? Are all the field devices in the same gas contract?

Don't even get me started on measurement units, like PSI, kPa, elephants per area of Frisbee….

One thought on “Timezone Pissing contest”

  1. My personal favorite was the Balancing needed for the measurement system. The real fun started when the plant/station was on the timezone divider, and one side used daylight savings time, and the other did not.

    Sweet memories.

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